问题标题: 酷町堂:Dev.C++

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为什么我写2705这一题

运行的时候弹出了一个叫    stl_algobase.h 的东西

// Core algorithmic facilities -*- C++ -*-

// Copyright (C) 2001-2014 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

/** @file bits/stl_algobase.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{algorithm}
 */

#ifndef _STL_ALGOBASE_H
#define _STL_ALGOBASE_H 1

#include <bits/c++config.h>
#include <bits/functexcept.h>
#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>
#include <ext/numeric_traits.h>
#include <bits/stl_pair.h>
#include <bits/stl_iterator_base_types.h>
#include <bits/stl_iterator_base_funcs.h>
#include <bits/stl_iterator.h>
#include <bits/concept_check.h>
#include <debug/debug.h>
#include <bits/move.h> // For std::swap and _GLIBCXX_MOVE
#include <bits/predefined_ops.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

#if __cplusplus < 201103L
  // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
  // nutshell, we are partially implementing the resolution of DR 187,
  // when it's safe, i.e., the value_types are equal.
  template<bool _BoolType>
    struct __iter_swap
    {
      template<typename _ForwardIterator1, typename _ForwardIterator2>
        static void
        iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
        {
          typedef typename iterator_traits<_ForwardIterator1>::value_type
            _ValueType1;
          _ValueType1 __tmp = _GLIBCXX_MOVE(*__a);
          *__a = _GLIBCXX_MOVE(*__b);
          *__b = _GLIBCXX_MOVE(__tmp);
    }
    };

  template<>
    struct __iter_swap<true>
    {
      template<typename _ForwardIterator1, typename _ForwardIterator2>
        static void 
        iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
        {
          swap(*__a, *__b);
        }
    };
#endif

  /**
   *  @brief Swaps the contents of two iterators.
   *  @ingroup mutating_algorithms
   *  @param  __a  An iterator.
   *  @param  __b  Another iterator.
   *  @return   Nothing.
   *
   *  This function swaps the values pointed to by two iterators, not the
   *  iterators themselves.
  */
  template<typename _ForwardIterator1, typename _ForwardIterator2>
    inline void
    iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
    {
      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator1>)
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator2>)

#if __cplusplus < 201103L
      typedef typename iterator_traits<_ForwardIterator1>::value_type
    _ValueType1;
      typedef typename iterator_traits<_ForwardIterator2>::value_type
    _ValueType2;

      __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
                  _ValueType2>)
      __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
                  _ValueType1>)

      typedef typename iterator_traits<_ForwardIterator1>::reference
    _ReferenceType1;
      typedef typename iterator_traits<_ForwardIterator2>::reference
    _ReferenceType2;
      std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value
    && __are_same<_ValueType1&, _ReferenceType1>::__value
    && __are_same<_ValueType2&, _ReferenceType2>::__value>::
    iter_swap(__a, __b);
#else
      swap(*__a, *__b);
#endif
    }

  /**
   *  @brief Swap the elements of two sequences.
   *  @ingroup mutating_algorithms
   *  @param  __first1  A forward iterator.
   *  @param  __last1   A forward iterator.
   *  @param  __first2  A forward iterator.
   *  @return   An iterator equal to @p first2+(last1-first1).
   *
   *  Swaps each element in the range @p [first1,last1) with the
   *  corresponding element in the range @p [first2,(last1-first1)).
   *  The ranges must not overlap.
  */
  template<typename _ForwardIterator1, typename _ForwardIterator2>
    _ForwardIterator2
    swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
        _ForwardIterator2 __first2)
    {
      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator1>)
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);

      for (; __first1 != __last1; ++__first1, ++__first2)
    std::iter_swap(__first1, __first2);
      return __first2;
    }

  /**
   *  @brief This does what you think it does.
   *  @ingroup sorting_algorithms
   *  @param  __a  A thing of arbitrary type.
   *  @param  __b  Another thing of arbitrary type.
   *  @return   The lesser of the parameters.
   *
   *  This is the simple classic generic implementation.  It will work on
   *  temporary expressions, since they are only evaluated once, unlike a
   *  preprocessor macro.
  */
  template<typename _Tp>
    inline const _Tp&
    min(const _Tp& __a, const _Tp& __b)
    {
      // concept requirements
      __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
      //return __b < __a ? __b : __a;
      if (__b < __a)
    return __b;
      return __a;
    }

  /**
   *  @brief This does what you think it does.
   *  @ingroup sorting_algorithms
   *  @param  __a  A thing of arbitrary type.
   *  @param  __b  Another thing of arbitrary type.
   *  @return   The greater of the parameters.
   *
   *  This is the simple classic generic implementation.  It will work on
   *  temporary expressions, since they are only evaluated once, unlike a
   *  preprocessor macro.
  */
  template<typename _Tp>
    inline const _Tp&
    max(const _Tp& __a, const _Tp& __b)
    {
      // concept requirements
      __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
      //return  __a < __b ? __b : __a;
      if (__a < __b)
    return __b;
      return __a;
    }

  /**
   *  @brief This does what you think it does.
   *  @ingroup sorting_algorithms
   *  @param  __a  A thing of arbitrary type.
   *  @param  __b  Another thing of arbitrary type.
   *  @param  __comp  A @link comparison_functors comparison functor@endlink.
   *  @return   The lesser of the parameters.
   *
   *  This will work on temporary expressions, since they are only evaluated
   *  once, unlike a preprocessor macro.
  */
  template<typename _Tp, typename _Compare>
    inline const _Tp&
    min(const _Tp& __a, const _Tp& __b, _Compare __comp)
    {
      //return __comp(__b, __a) ? __b : __a;
      if (__comp(__b, __a))
    return __b;
      return __a;
    }

  /**
   *  @brief This does what you think it does.
   *  @ingroup sorting_algorithms
   *  @param  __a  A thing of arbitrary type.
   *  @param  __b  Another thing of arbitrary type.
   *  @param  __comp  A @link comparison_functors comparison functor@endlink.
   *  @return   The greater of the parameters.
   *
   *  This will work on temporary expressions, since they are only evaluated
   *  once, unlike a preprocessor macro.
  */
  template<typename _Tp, typename _Compare>
    inline const _Tp&
    max(const _Tp& __a, const _Tp& __b, _Compare __comp)
    {
      //return __comp(__a, __b) ? __b : __a;
      if (__comp(__a, __b))
    return __b;
      return __a;
    }

  // If _Iterator is a __normal_iterator return its base (a plain pointer,
  // normally) otherwise return it untouched.  See copy, fill, ... 
  template<typename _Iterator>
    struct _Niter_base
    : _Iter_base<_Iterator, __is_normal_iterator<_Iterator>::__value>
    { };

  template<typename _Iterator>
    inline typename _Niter_base<_Iterator>::iterator_type
    __niter_base(_Iterator __it)
    { return std::_Niter_base<_Iterator>::_S_base(__it); }

  // Likewise, for move_iterator.
  template<typename _Iterator>
    struct _Miter_base
    : _Iter_base<_Iterator, __is_move_iterator<_Iterator>::__value>
    { };

  template<typename _Iterator>
    inline typename _Miter_base<_Iterator>::iterator_type
    __miter_base(_Iterator __it)
    { return std::_Miter_base<_Iterator>::_S_base(__it); }

  // All of these auxiliary structs serve two purposes.  (1) Replace
  // calls to copy with memmove whenever possible.  (Memmove, not memcpy,
  // because the input and output ranges are permitted to overlap.)
  // (2) If we're using random access iterators, then write the loop as
  // a for loop with an explicit count.

  template<bool, bool, typename>
    struct __copy_move
    {
      template<typename _II, typename _OI>
        static _OI
        __copy_m(_II __first, _II __last, _OI __result)
        {
      for (; __first != __last; ++__result, ++__first)
        *__result = *__first;
      return __result;
    }
    };

#if __cplusplus >= 201103L
  template<typename _Category>
    struct __copy_move<true, false, _Category>
    {
      template<typename _II, typename _OI>
        static _OI
        __copy_m(_II __first, _II __last, _OI __result)
        {
      for (; __first != __last; ++__result, ++__first)
        *__result = std::move(*__first);
      return __result;
    }
    };
#endif

  template<>
    struct __copy_move<false, false, random_access_iterator_tag>
    {
      template<typename _II, typename _OI>
        static _OI
        __copy_m(_II __first, _II __last, _OI __result)
        { 
      typedef typename iterator_traits<_II>::difference_type _Distance;
      for(_Distance __n = __last - __first; __n > 0; --__n)
        {
          *__result = *__first;
          ++__first;
          ++__result;
        }
      return __result;
    }
    };

#if __cplusplus >= 201103L
  template<>
    struct __copy_move<true, false, random_access_iterator_tag>
    {
      template<typename _II, typename _OI>
        static _OI
        __copy_m(_II __first, _II __last, _OI __result)
        { 
      typedef typename iterator_traits<_II>::difference_type _Distance;
      for(_Distance __n = __last - __first; __n > 0; --__n)
        {
          *__result = std::move(*__first);
          ++__first;
          ++__result;
        }
      return __result;
    }
    };
#endif

  template<bool _IsMove>
    struct __copy_move<_IsMove, true, random_access_iterator_tag>
    {
      template<typename _Tp>
        static _Tp*
        __copy_m(const _Tp* __first, const _Tp* __last, _Tp* __result)
        {
#if __cplusplus >= 201103L
      // trivial types can have deleted assignment
      static_assert( is_copy_assignable<_Tp>::value,
                     "type is not assignable" );
#endif
      const ptrdiff_t _Num = __last - __first;
      if (_Num)
        __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
      return __result + _Num;
    }
    };

  template<bool _IsMove, typename _II, typename _OI>
    inline _OI
    __copy_move_a(_II __first, _II __last, _OI __result)
    {
      typedef typename iterator_traits<_II>::value_type _ValueTypeI;
      typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
      typedef typename iterator_traits<_II>::iterator_category _Category;
      const bool __simple = (__is_trivial(_ValueTypeI)
                         && __is_pointer<_II>::__value
                         && __is_pointer<_OI>::__value
                 && __are_same<_ValueTypeI, _ValueTypeO>::__value);

      return std::__copy_move<_IsMove, __simple,
                          _Category>::__copy_m(__first, __last, __result);
    }

  // Helpers for streambuf iterators (either istream or ostream).
  // NB: avoid including <iosfwd>, relatively large.
  template<typename _CharT>
    struct char_traits;

  template<typename _CharT, typename _Traits>
    class istreambuf_iterator;

  template<typename _CharT, typename _Traits>
    class ostreambuf_iterator;

  template<bool _IsMove, typename _CharT>
    typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 
         ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
    __copy_move_a2(_CharT*, _CharT*,
           ostreambuf_iterator<_CharT, char_traits<_CharT> >);

  template<bool _IsMove, typename _CharT>
    typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 
         ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
    __copy_move_a2(const _CharT*, const _CharT*,
           ostreambuf_iterator<_CharT, char_traits<_CharT> >);

  template<bool _IsMove, typename _CharT>
    typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
                    _CharT*>::__type
    __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
           istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);

  template<bool _IsMove, typename _II, typename _OI>
    inline _OI
    __copy_move_a2(_II __first, _II __last, _OI __result)
    {
      return _OI(std::__copy_move_a<_IsMove>(std::__niter_base(__first),
                         std::__niter_base(__last),
                         std::__niter_base(__result)));
    }

  /**
   *  @brief Copies the range [first,last) into result.
   *  @ingroup mutating_algorithms
   *  @param  __first  An input iterator.
   *  @param  __last   An input iterator.
   *  @param  __result An output iterator.
   *  @return   result + (first - last)
   *
   *  This inline function will boil down to a call to @c memmove whenever
   *  possible.  Failing that, if random access iterators are passed, then the
   *  loop count will be known (and therefore a candidate for compiler
   *  optimizations such as unrolling).  Result may not be contained within
   *  [first,last); the copy_backward function should be used instead.
   *
   *  Note that the end of the output range is permitted to be contained
   *  within [first,last).
  */
  template<typename _II, typename _OI>
    inline _OI
    copy(_II __first, _II __last, _OI __result)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_II>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OI,
        typename iterator_traits<_II>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return (std::__copy_move_a2<__is_move_iterator<_II>::__value>
          (std::__miter_base(__first), std::__miter_base(__last),
           __result));
    }

#if __cplusplus >= 201103L
  /**
   *  @brief Moves the range [first,last) into result.
   *  @ingroup mutating_algorithms
   *  @param  __first  An input iterator.
   *  @param  __last   An input iterator.
   *  @param  __result An output iterator.
   *  @return   result + (first - last)
   *
   *  This inline function will boil down to a call to @c memmove whenever
   *  possible.  Failing that, if random access iterators are passed, then the
   *  loop count will be known (and therefore a candidate for compiler
   *  optimizations such as unrolling).  Result may not be contained within
   *  [first,last); the move_backward function should be used instead.
   *
   *  Note that the end of the output range is permitted to be contained
   *  within [first,last).
  */
  template<typename _II, typename _OI>
    inline _OI
    move(_II __first, _II __last, _OI __result)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_II>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OI,
        typename iterator_traits<_II>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return std::__copy_move_a2<true>(std::__miter_base(__first),
                       std::__miter_base(__last), __result);
    }

#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
#else
#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
#endif

  template<bool, bool, typename>
    struct __copy_move_backward
    {
      template<typename _BI1, typename _BI2>
        static _BI2
        __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
        {
      while (__first != __last)
        *--__result = *--__last;
      return __result;
    }
    };

#if __cplusplus >= 201103L
  template<typename _Category>
    struct __copy_move_backward<true, false, _Category>
    {
      template<typename _BI1, typename _BI2>
        static _BI2
        __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
        {
      while (__first != __last)
        *--__result = std::move(*--__last);
      return __result;
    }
    };
#endif

  template<>
    struct __copy_move_backward<false, false, random_access_iterator_tag>
    {
      template<typename _BI1, typename _BI2>
        static _BI2
        __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
        {
      typename iterator_traits<_BI1>::difference_type __n;
      for (__n = __last - __first; __n > 0; --__n)
        *--__result = *--__last;
      return __result;
    }
    };

#if __cplusplus >= 201103L
  template<>
    struct __copy_move_backward<true, false, random_access_iterator_tag>
    {
      template<typename _BI1, typename _BI2>
        static _BI2
        __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
        {
      typename iterator_traits<_BI1>::difference_type __n;
      for (__n = __last - __first; __n > 0; --__n)
        *--__result = std::move(*--__last);
      return __result;
    }
    };
#endif

  template<bool _IsMove>
    struct __copy_move_backward<_IsMove, true, random_access_iterator_tag>
    {
      template<typename _Tp>
        static _Tp*
        __copy_move_b(const _Tp* __first, const _Tp* __last, _Tp* __result)
        {
#if __cplusplus >= 201103L
      // trivial types can have deleted assignment
      static_assert( is_copy_assignable<_Tp>::value,
                     "type is not assignable" );
#endif
      const ptrdiff_t _Num = __last - __first;
      if (_Num)
        __builtin_memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
      return __result - _Num;
    }
    };

  template<bool _IsMove, typename _BI1, typename _BI2>
    inline _BI2
    __copy_move_backward_a(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      typedef typename iterator_traits<_BI1>::value_type _ValueType1;
      typedef typename iterator_traits<_BI2>::value_type _ValueType2;
      typedef typename iterator_traits<_BI1>::iterator_category _Category;
      const bool __simple = (__is_trivial(_ValueType1)
                         && __is_pointer<_BI1>::__value
                         && __is_pointer<_BI2>::__value
                 && __are_same<_ValueType1, _ValueType2>::__value);

      return std::__copy_move_backward<_IsMove, __simple,
                                   _Category>::__copy_move_b(__first,
                                 __last,
                                 __result);
    }

  template<bool _IsMove, typename _BI1, typename _BI2>
    inline _BI2
    __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      return _BI2(std::__copy_move_backward_a<_IsMove>
          (std::__niter_base(__first), std::__niter_base(__last),
           std::__niter_base(__result)));
    }

  /**
   *  @brief Copies the range [first,last) into result.
   *  @ingroup mutating_algorithms
   *  @param  __first  A bidirectional iterator.
   *  @param  __last   A bidirectional iterator.
   *  @param  __result A bidirectional iterator.
   *  @return   result - (first - last)
   *
   *  The function has the same effect as copy, but starts at the end of the
   *  range and works its way to the start, returning the start of the result.
   *  This inline function will boil down to a call to @c memmove whenever
   *  possible.  Failing that, if random access iterators are passed, then the
   *  loop count will be known (and therefore a candidate for compiler
   *  optimizations such as unrolling).
   *
   *  Result may not be in the range (first,last].  Use copy instead.  Note
   *  that the start of the output range may overlap [first,last).
  */
  template<typename _BI1, typename _BI2>
    inline _BI2
    copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      // concept requirements
      __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
      __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
      __glibcxx_function_requires(_ConvertibleConcept<
        typename iterator_traits<_BI1>::value_type,
        typename iterator_traits<_BI2>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return (std::__copy_move_backward_a2<__is_move_iterator<_BI1>::__value>
          (std::__miter_base(__first), std::__miter_base(__last),
           __result));
    }

#if __cplusplus >= 201103L
  /**
   *  @brief Moves the range [first,last) into result.
   *  @ingroup mutating_algorithms
   *  @param  __first  A bidirectional iterator.
   *  @param  __last   A bidirectional iterator.
   *  @param  __result A bidirectional iterator.
   *  @return   result - (first - last)
   *
   *  The function has the same effect as move, but starts at the end of the
   *  range and works its way to the start, returning the start of the result.
   *  This inline function will boil down to a call to @c memmove whenever
   *  possible.  Failing that, if random access iterators are passed, then the
   *  loop count will be known (and therefore a candidate for compiler
   *  optimizations such as unrolling).
   *
   *  Result may not be in the range (first,last].  Use move instead.  Note
   *  that the start of the output range may overlap [first,last).
  */
  template<typename _BI1, typename _BI2>
    inline _BI2
    move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      // concept requirements
      __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
      __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
      __glibcxx_function_requires(_ConvertibleConcept<
        typename iterator_traits<_BI1>::value_type,
        typename iterator_traits<_BI2>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      return std::__copy_move_backward_a2<true>(std::__miter_base(__first),
                        std::__miter_base(__last),
                        __result);
    }

#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
#else
#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
#endif

  template<typename _ForwardIterator, typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
    __fill_a(_ForwardIterator __first, _ForwardIterator __last,
         const _Tp& __value)
    {
      for (; __first != __last; ++__first)
    *__first = __value;
    }

  template<typename _ForwardIterator, typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
    __fill_a(_ForwardIterator __first, _ForwardIterator __last,
         const _Tp& __value)
    {
      const _Tp __tmp = __value;
      for (; __first != __last; ++__first)
    *__first = __tmp;
    }

  // Specialization: for char types we can use memset.
  template<typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
    __fill_a(_Tp* __first, _Tp* __last, const _Tp& __c)
    {
      const _Tp __tmp = __c;
      __builtin_memset(__first, static_cast<unsigned char>(__tmp),
               __last - __first);
    }

  /**
   *  @brief Fills the range [first,last) with copies of value.
   *  @ingroup mutating_algorithms
   *  @param  __first  A forward iterator.
   *  @param  __last   A forward iterator.
   *  @param  __value  A reference-to-const of arbitrary type.
   *  @return   Nothing.
   *
   *  This function fills a range with copies of the same value.  For char
   *  types filling contiguous areas of memory, this becomes an inline call
   *  to @c memset or @c wmemset.
  */
  template<typename _ForwardIterator, typename _Tp>
    inline void
    fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
    {
      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator>)
      __glibcxx_requires_valid_range(__first, __last);

      std::__fill_a(std::__niter_base(__first), std::__niter_base(__last),
            __value);
    }

  template<typename _OutputIterator, typename _Size, typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
    __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
    {
      for (__decltype(__n + 0) __niter = __n;
       __niter > 0; --__niter, ++__first)
    *__first = __value;
      return __first;
    }

  template<typename _OutputIterator, typename _Size, typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
    __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
    {
      const _Tp __tmp = __value;
      for (__decltype(__n + 0) __niter = __n;
       __niter > 0; --__niter, ++__first)
    *__first = __tmp;
      return __first;
    }

  template<typename _Size, typename _Tp>
    inline typename
    __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, _Tp*>::__type
    __fill_n_a(_Tp* __first, _Size __n, const _Tp& __c)
    {
      std::__fill_a(__first, __first + __n, __c);
      return __first + __n;
    }

  /**
   *  @brief Fills the range [first,first+n) with copies of value.
   *  @ingroup mutating_algorithms
   *  @param  __first  An output iterator.
   *  @param  __n      The count of copies to perform.
   *  @param  __value  A reference-to-const of arbitrary type.
   *  @return   The iterator at first+n.
   *
   *  This function fills a range with copies of the same value.  For char
   *  types filling contiguous areas of memory, this becomes an inline call
   *  to @c memset or @ wmemset.
   *
   *  _GLIBCXX_RESOLVE_LIB_DEFECTS
   *  DR 865. More algorithms that throw away information
  */
  template<typename _OI, typename _Size, typename _Tp>
    inline _OI
    fill_n(_OI __first, _Size __n, const _Tp& __value)
    {
      // concept requirements
      __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)

      return _OI(std::__fill_n_a(std::__niter_base(__first), __n, __value));
    }

  template<bool _BoolType>
    struct __equal
    {
      template<typename _II1, typename _II2>
        static bool
        equal(_II1 __first1, _II1 __last1, _II2 __first2)
        {
      for (; __first1 != __last1; ++__first1, ++__first2)
        if (!(*__first1 == *__first2))
          return false;
      return true;
    }
    };

  template<>
    struct __equal<true>
    {
      template<typename _Tp>
        static bool
        equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
        {
      return !__builtin_memcmp(__first1, __first2, sizeof(_Tp)
                   * (__last1 - __first1));
    }
    };

  template<typename _II1, typename _II2>
    inline bool
    __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
    {
      typedef typename iterator_traits<_II1>::value_type _ValueType1;
      typedef typename iterator_traits<_II2>::value_type _ValueType2;
      const bool __simple = ((__is_integer<_ValueType1>::__value
                  || __is_pointer<_ValueType1>::__value)
                         && __is_pointer<_II1>::__value
                         && __is_pointer<_II2>::__value
                 && __are_same<_ValueType1, _ValueType2>::__value);

      return std::__equal<__simple>::equal(__first1, __last1, __first2);
    }

  template<typename, typename>
    struct __lc_rai
    {
      template<typename _II1, typename _II2>
        static _II1
        __newlast1(_II1, _II1 __last1, _II2, _II2)
        { return __last1; }

      template<typename _II>
        static bool
        __cnd2(_II __first, _II __last)
        { return __first != __last; }
    };

  template<>
    struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
    {
      template<typename _RAI1, typename _RAI2>
        static _RAI1
        __newlast1(_RAI1 __first1, _RAI1 __last1,
           _RAI2 __first2, _RAI2 __last2)
        {
      const typename iterator_traits<_RAI1>::difference_type
        __diff1 = __last1 - __first1;
      const typename iterator_traits<_RAI2>::difference_type
        __diff2 = __last2 - __first2;
      return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
    }

      template<typename _RAI>
        static bool
        __cnd2(_RAI, _RAI)
        { return true; }
    };

  template<typename _II1, typename _II2, typename _Compare>
    bool
    __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
                   _II2 __first2, _II2 __last2,
                   _Compare __comp)
    {
      typedef typename iterator_traits<_II1>::iterator_category _Category1;
      typedef typename iterator_traits<_II2>::iterator_category _Category2;
      typedef std::__lc_rai<_Category1, _Category2> __rai_type;

      __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
      for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
       ++__first1, ++__first2)
    {
      if (__comp(__first1, __first2))
        return true;
      if (__comp(__first2, __first1))
        return false;
    }
      return __first1 == __last1 && __first2 != __last2;
    }

  template<bool _BoolType>
    struct __lexicographical_compare
    {
      template<typename _II1, typename _II2>
        static bool __lc(_II1, _II1, _II2, _II2);
    };

  template<bool _BoolType>
    template<typename _II1, typename _II2>
      bool
      __lexicographical_compare<_BoolType>::
      __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
      {
    return std::__lexicographical_compare_impl(__first1, __last1,
                           __first2, __last2,
                    __gnu_cxx::__ops::__iter_less_iter());
      }

  template<>
    struct __lexicographical_compare<true>
    {
      template<typename _Tp, typename _Up>
        static bool
        __lc(const _Tp* __first1, const _Tp* __last1,
         const _Up* __first2, const _Up* __last2)
    {
      const size_t __len1 = __last1 - __first1;
      const size_t __len2 = __last2 - __first2;
      const int __result = __builtin_memcmp(__first1, __first2,
                        std::min(__len1, __len2));
      return __result != 0 ? __result < 0 : __len1 < __len2;
    }
    };

  template<typename _II1, typename _II2>
    inline bool
    __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
                  _II2 __first2, _II2 __last2)
    {
      typedef typename iterator_traits<_II1>::value_type _ValueType1;
      typedef typename iterator_traits<_II2>::value_type _ValueType2;
      const bool __simple =
    (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
     && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
     && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
     && __is_pointer<_II1>::__value
     && __is_pointer<_II2>::__value);

      return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
                                __first2, __last2);
    }

  template<typename _ForwardIterator, typename _Tp, typename _Compare>
    _ForwardIterator
    __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
          const _Tp& __val, _Compare __comp)
    {
      typedef typename iterator_traits<_ForwardIterator>::difference_type
    _DistanceType;

      _DistanceType __len = std::distance(__first, __last);

      while (__len > 0)
    {
      _DistanceType __half = __len >> 1;
      _ForwardIterator __middle = __first;
      std::advance(__middle, __half);
      if (__comp(__middle, __val))
        {
          __first = __middle;
          ++__first;
          __len = __len - __half - 1;
        }
      else
        __len = __half;
    }
      return __first;
    }

  /**
   *  @brief Finds the first position in which @a val could be inserted
   *         without changing the ordering.
   *  @param  __first   An iterator.
   *  @param  __last    Another iterator.
   *  @param  __val     The search term.
   *  @return         An iterator pointing to the first element <em>not less
   *                  than</em> @a val, or end() if every element is less than 
   *                  @a val.
   *  @ingroup binary_search_algorithms
  */
  template<typename _ForwardIterator, typename _Tp>
    inline _ForwardIterator
    lower_bound(_ForwardIterator __first, _ForwardIterator __last,
        const _Tp& __val)
    {
      // concept requirements
      __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
      __glibcxx_function_requires(_LessThanOpConcept<
        typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
      __glibcxx_requires_partitioned_lower(__first, __last, __val);

      return std::__lower_bound(__first, __last, __val,
                __gnu_cxx::__ops::__iter_less_val());
    }

  /// This is a helper function for the sort routines and for random.tcc.
  //  Precondition: __n > 0.
  inline _GLIBCXX_CONSTEXPR int
  __lg(int __n)
  { return sizeof(int) * __CHAR_BIT__  - 1 - __builtin_clz(__n); }

  inline _GLIBCXX_CONSTEXPR unsigned
  __lg(unsigned __n)
  { return sizeof(int) * __CHAR_BIT__  - 1 - __builtin_clz(__n); }

  inline _GLIBCXX_CONSTEXPR long
  __lg(long __n)
  { return sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }

  inline _GLIBCXX_CONSTEXPR unsigned long
  __lg(unsigned long __n)
  { return sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }

  inline _GLIBCXX_CONSTEXPR long long
  __lg(long long __n)
  { return sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }

  inline _GLIBCXX_CONSTEXPR unsigned long long
  __lg(unsigned long long __n)
  { return sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }

_GLIBCXX_END_NAMESPACE_VERSION

_GLIBCXX_BEGIN_NAMESPACE_ALGO

  /**
   *  @brief Tests a range for element-wise equality.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @return   A boolean true or false.
   *
   *  This compares the elements of two ranges using @c == and returns true or
   *  false depending on whether all of the corresponding elements of the
   *  ranges are equal.
  */
  template<typename _II1, typename _II2>
    inline bool
    equal(_II1 __first1, _II1 __last1, _II2 __first2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_II1>)
      __glibcxx_function_requires(_InputIteratorConcept<_II2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_II1>::value_type,
        typename iterator_traits<_II2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);

      return std::__equal_aux(std::__niter_base(__first1),
                  std::__niter_base(__last1),
                  std::__niter_base(__first2));
    }

  /**
   *  @brief Tests a range for element-wise equality.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param __binary_pred A binary predicate @link functors
   *                  functor@endlink.
   *  @return         A boolean true or false.
   *
   *  This compares the elements of two ranges using the binary_pred
   *  parameter, and returns true or
   *  false depending on whether all of the corresponding elements of the
   *  ranges are equal.
  */
  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
    inline bool
    equal(_IIter1 __first1, _IIter1 __last1,
      _IIter2 __first2, _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
      __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
      __glibcxx_requires_valid_range(__first1, __last1);

      for (; __first1 != __last1; ++__first1, ++__first2)
    if (!bool(__binary_pred(*__first1, *__first2)))
      return false;
      return true;
    }

#if __cplusplus > 201103L

#define __cpp_lib_robust_nonmodifying_seq_ops 201304

  /**
   *  @brief Tests a range for element-wise equality.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @return   A boolean true or false.
   *
   *  This compares the elements of two ranges using @c == and returns true or
   *  false depending on whether all of the corresponding elements of the
   *  ranges are equal.
  */
  template<typename _II1, typename _II2>
    inline bool
    equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_II1>)
      __glibcxx_function_requires(_InputIteratorConcept<_II2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_II1>::value_type,
        typename iterator_traits<_II2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      using _RATag = random_access_iterator_tag;
      using _Cat1 = typename iterator_traits<_II1>::iterator_category;
      using _Cat2 = typename iterator_traits<_II2>::iterator_category;
      using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
      if (_RAIters())
    {
      auto __d1 = std::distance(__first1, __last1);
      auto __d2 = std::distance(__first2, __last2);
      if (__d1 != __d2)
        return false;
      return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
    }

      for (; __first1 != __last1 && __first2 != __last2; ++__first1, ++__first2)
    if (!(*__first1 == *__first2))
      return false;
      return __first1 == __last1 && __first2 == __last2;
    }

  /**
   *  @brief Tests a range for element-wise equality.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @param __binary_pred A binary predicate @link functors
   *                  functor@endlink.
   *  @return         A boolean true or false.
   *
   *  This compares the elements of two ranges using the binary_pred
   *  parameter, and returns true or
   *  false depending on whether all of the corresponding elements of the
   *  ranges are equal.
  */
  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
    inline bool
    equal(_IIter1 __first1, _IIter1 __last1,
      _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
      __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      using _RATag = random_access_iterator_tag;
      using _Cat1 = typename iterator_traits<_IIter1>::iterator_category;
      using _Cat2 = typename iterator_traits<_IIter2>::iterator_category;
      using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
      if (_RAIters())
    {
      auto __d1 = std::distance(__first1, __last1);
      auto __d2 = std::distance(__first2, __last2);
      if (__d1 != __d2)
        return false;
      return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
                       __binary_pred);
    }

      for (; __first1 != __last1 && __first2 != __last2; ++__first1, ++__first2)
    if (!bool(__binary_pred(*__first1, *__first2)))
      return false;
      return __first1 == __last1 && __first2 == __last2;
    }
#endif

  /**
   *  @brief Performs @b dictionary comparison on ranges.
   *  @ingroup sorting_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @return   A boolean true or false.
   *
   *  <em>Returns true if the sequence of elements defined by the range
   *  [first1,last1) is lexicographically less than the sequence of elements
   *  defined by the range [first2,last2).  Returns false otherwise.</em>
   *  (Quoted from [25.3.8]/1.)  If the iterators are all character pointers,
   *  then this is an inline call to @c memcmp.
  */
  template<typename _II1, typename _II2>
    inline bool
    lexicographical_compare(_II1 __first1, _II1 __last1,
                _II2 __first2, _II2 __last2)
    {
#ifdef _GLIBCXX_CONCEPT_CHECKS
      // concept requirements
      typedef typename iterator_traits<_II1>::value_type _ValueType1;
      typedef typename iterator_traits<_II2>::value_type _ValueType2;
#endif
      __glibcxx_function_requires(_InputIteratorConcept<_II1>)
      __glibcxx_function_requires(_InputIteratorConcept<_II2>)
      __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
      __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      return std::__lexicographical_compare_aux(std::__niter_base(__first1),
                        std::__niter_base(__last1),
                        std::__niter_base(__first2),
                        std::__niter_base(__last2));
    }

  /**
   *  @brief Performs @b dictionary comparison on ranges.
   *  @ingroup sorting_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @param  __comp  A @link comparison_functors comparison functor@endlink.
   *  @return   A boolean true or false.
   *
   *  The same as the four-parameter @c lexicographical_compare, but uses the
   *  comp parameter instead of @c <.
  */
  template<typename _II1, typename _II2, typename _Compare>
    inline bool
    lexicographical_compare(_II1 __first1, _II1 __last1,
                _II2 __first2, _II2 __last2, _Compare __comp)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_II1>)
      __glibcxx_function_requires(_InputIteratorConcept<_II2>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      return std::__lexicographical_compare_impl
    (__first1, __last1, __first2, __last2,
     __gnu_cxx::__ops::__iter_comp_iter(__comp));
    }

  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    pair<_InputIterator1, _InputIterator2>
    __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
           _InputIterator2 __first2, _BinaryPredicate __binary_pred)
    {
      while (__first1 != __last1 && __binary_pred(__first1, __first2))
        {
      ++__first1;
      ++__first2;
        }
      return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
    }

  /**
   *  @brief Finds the places in ranges which don't match.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @return   A pair of iterators pointing to the first mismatch.
   *
   *  This compares the elements of two ranges using @c == and returns a pair
   *  of iterators.  The first iterator points into the first range, the
   *  second iterator points into the second range, and the elements pointed
   *  to by the iterators are not equal.
  */
  template<typename _InputIterator1, typename _InputIterator2>
    inline pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_InputIterator1>::value_type,
        typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);

      return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
                 __gnu_cxx::__ops::__iter_equal_to_iter());
    }

  /**
   *  @brief Finds the places in ranges which don't match.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param __binary_pred A binary predicate @link functors
   *         functor@endlink.
   *  @return   A pair of iterators pointing to the first mismatch.
   *
   *  This compares the elements of two ranges using the binary_pred
   *  parameter, and returns a pair
   *  of iterators.  The first iterator points into the first range, the
   *  second iterator points into the second range, and the elements pointed
   *  to by the iterators are not equal.
  */
  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    inline pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2, _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);

      return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
    __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
    }

#if __cplusplus > 201103L

  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    pair<_InputIterator1, _InputIterator2>
    __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
           _InputIterator2 __first2, _InputIterator2 __last2,
           _BinaryPredicate __binary_pred)
    {
      while (__first1 != __last1 && __first2 != __last2
         && __binary_pred(__first1, __first2))
        {
      ++__first1;
      ++__first2;
        }
      return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
    }

  /**
   *  @brief Finds the places in ranges which don't match.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @return   A pair of iterators pointing to the first mismatch.
   *
   *  This compares the elements of two ranges using @c == and returns a pair
   *  of iterators.  The first iterator points into the first range, the
   *  second iterator points into the second range, and the elements pointed
   *  to by the iterators are not equal.
  */
  template<typename _InputIterator1, typename _InputIterator2>
    inline pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2, _InputIterator2 __last2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_InputIterator1>::value_type,
        typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
                 __gnu_cxx::__ops::__iter_equal_to_iter());
    }

  /**
   *  @brief Finds the places in ranges which don't match.
   *  @ingroup non_mutating_algorithms
   *  @param  __first1  An input iterator.
   *  @param  __last1   An input iterator.
   *  @param  __first2  An input iterator.
   *  @param  __last2   An input iterator.
   *  @param __binary_pred A binary predicate @link functors
   *         functor@endlink.
   *  @return   A pair of iterators pointing to the first mismatch.
   *
   *  This compares the elements of two ranges using the binary_pred
   *  parameter, and returns a pair
   *  of iterators.  The first iterator points into the first range, the
   *  second iterator points into the second range, and the elements pointed
   *  to by the iterators are not equal.
  */
  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    inline pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2, _InputIterator2 __last2,
         _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
                 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
    }
#endif

_GLIBCXX_END_NAMESPACE_ALGO
} // namespace std

// NB: This file is included within many other C++ includes, as a way
// of getting the base algorithms. So, make sure that parallel bits
// come in too if requested. 
#ifdef _GLIBCXX_PARALLEL
# include <parallel/algobase.h>
#endif

#endif

 

 

 

 

 

 

 

下面是我写的2705代码:

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int n,sum[1100];
struct gys{
    string name;
    int cl,cl1,cl2;
}a[70];
int main(){
cin>>n;
for(int i=1;i<=n;i++){
    cin>>a[i].name>>a[i].cl>>a[i].cl1>>a[i].cl2;
    if(a[i].cl!=0&&a[i].cl1!=0&&a[i].cl2!=0){
        sum[i]=sum[i]+a[i].cl+a[i].cl1+a[i].cl2;
    }
}
sort(a+1,a+n+1);
for(int i=1;i<=1;i++){
    cout<<a[i].name<<" "<<a[i].cl<<" "<<a[i].cl1<<" "<<a[i].cl2; 
}
return 0;
}

有没有谁知道这是什么

@酷町侠 @臧鸿志 @葛新


1
已采纳
邹昊轩
邹昊轩
资深光能
资深光能

我也遇到过!!!千万不要删了!!!

我删了一下,后果不堪设想!!!你可以强制关机||问老师||修改代码。

1
1
李明阳
李明阳
初级光能
初级光能

我以前也这样过 把c++删了重下就好了

望采纳

1
1
邓涵睿
邓涵睿
中级天翼
中级天翼

不管它就行了,你是要找错吗

1
1
陈曦
陈曦
资深天翼
资深天翼

我也遇到过!说明你的程序编译错误,或数组太大。

我以前遇到的原因就是程序编译错误

1
吕若朴
吕若朴
中级光能
中级光能

你就是写错了,但是程序多管闲事【滑稽】

1
刘英杰
刘英杰
新手天翼
新手天翼

那可能是你的系统版本或者是C++版本出了故障,试着关机之后更新系统或C++版本再进行尝试

1
徐子宸
徐子宸
中级天翼
中级天翼

用sort写就有可能出现这种情况

0
王子逸
王子逸
新手天翼
新手天翼

你的函数错了,系统在提醒你

0
岳成浩
岳成浩
资深守护
资深守护

有时候我写着写着就突然蹦出来了

0
武建豪
武建豪
中级天翼
中级天翼

STL标准中没有区分基本算法或复杂算法,单SGI把常用的一些算法定义在<stl_algobase.h>只中,其他算法定义在<stl_algo.h>中。

stl_algobase.h中的算法,比较值得学习的是copy(),它“无所不用其极”的改善效率。copy的目的是复制一段元素到指定区间,复制操作最容易想到赋值操作符=,但是有的赋值操作符=是trivial的,可以直接拷贝。关于赋值操作符=是不是trivial的,可以参考“Memberwise copy(深拷贝)与Bitwise copy(浅拷贝)的区别”。


Memberwise copy: 在初始化一个对象期间,基类的构造函数被调用,成员变量被调用,如果它们有构造函数的时候,它们的构造函数被调用,这个过程是一个递归的过程.


Bitwise copy: 原内存拷贝.例子,给定一个对象object,它的类型是class Base.对象object占用10字节的内存,地址从0x0到0x9.如果还有一个对象objectTwo,类型也是class Base.那么执行objectTwo = object;如果使用Bitwise拷贝语义,那么将会拷贝从0x0到0x9的数据到objectTwo的内存地址,.也就是说Bitwise是字节到字节的拷贝.

对于默认的拷贝构造函数不会使用深拷贝,它只是使用浅拷贝.这意味着类的所有的成员是一层深度的拷贝而已。如果你的类或结构体成员中只是包含基本的数据类型例如int, float, char,那么Memberwise copy与Bitwise copy基本是相同的。但如果类中有指针存在,那么你可能会遇到问题。


例如下面的例子:

class A
{
   int m1;
   double d1;
   char* pString;
};

如果你创建两个这样的类对象,class A  a, b;并且你给a赋值,
a.mi = 6;
a.d1 = 10.123;
a.pString = new char[10];
astrcpy(a.pString, "test");//这里是浅拷贝


如果执行b = a;那么会把对象a的每一个成员的值赋值给b的每个成员。
b.m1 = a.m1;
b.d1 = a.d1;
b.pString = a.pString;//现在对象a和b的成员pString都执向相同的内存,删除任一个内存都会析放另一个对象的内存。


所以你需要深拷贝,它不是拷贝的内存地址而是拷贝内存地址的内容。一个默认的拷贝构造函数经常执行浅拷贝,只有拥有
自己的拷贝函数才可以实现深拷贝。

补充:

在BitWise Copy Sematics中,因为是按位拷贝的(内存复制),所以那些整数、数组等都会拷贝,新得到的类和原来的类完全一样。但是需要注意一点,如果有指针时,例如

Class Test{
……;
char * p;
};
Test B=A;//A是Test类的对象


这时候如果是BitWise Copy,那么A和B中的指针p就会指向同一内存,如果内存在构造函数中释放,那么另一个类的指针将失效。

在一下4中情况,不要BitWise Copy

1、当Class内的成员变量是一个类,这各类声明了Copy Constructor(不是编译器默认合成)时。

2、当Class继承自一个Base Class时,而Base Class存在Copy Constructor时(不是编译器默认合成)。

3、当Class中声明有virtual function时

4、当Class继承自一个继承串链,其中一个或多个virtual Base Class时。


下面是copy调用过程的讲解。


// Filename:    stl_algobase.h
 
// 这个文件中定义的都是一些最常用的算法, 我仅仅给出一个思路,
// 不进行详尽讲解, 具体算法请参考算法书籍, 推荐《算法导论》
// 另外, 对于基础薄弱的, 推荐《大话数据结构》, 此书我读了一下
// 试读章节, 适合初学者学习
 
/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */
 
/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */
 
/*#ifndef __SGI_STL_INTERNAL_ALGOBASE_H
#define __SGI_STL_INTERNAL_ALGOBASE_H
 
#ifndef __STL_CONFIG_H
#include <stl_config.h>
#endif
#ifndef __SGI_STL_INTERNAL_RELOPS
#include <stl_relops.h>
#endif
#ifndef __SGI_STL_INTERNAL_PAIR_H
#include <stl_pair.h>
#endif
#ifndef __TYPE_TRAITS_H_
#include <type_traits.h>
#endif
 
#include <string.h>
#include <limits.h>
#include <stdlib.h>
#include <stddef.h>
#include <new.h>
#include <iostream.h>
 
#ifndef __SGI_STL_INTERNAL_ITERATOR_H
#include <stl_iterator.h>
#endif
 
__STL_BEGIN_NAMESPACE
 
// 第三个参数为什么为指针参见<stl_iterator.h>
template <class ForwardIterator1, class ForwardIterator2, class T>
inline void __iter_swap(ForwardIterator1 a, ForwardIterator2 b, T*)
{
  // 这里交换的其实是内部对象
  T tmp = *a;
  *a = *b;
  *b = tmp;
}
 
template <class ForwardIterator1, class ForwardIterator2>
inline void iter_swap(ForwardIterator1 a, ForwardIterator2 b)
{
  // 型别以第一个为准
  __iter_swap(a, b, value_type(a));
}
 
// 进行交换操作, 使用的是operator =()
template <class T>
inline void swap(T& a, T& b)
{
  T tmp = a;
  a = b;
  b = tmp;
}
 
#ifndef __BORLANDC__
 
#undef min
#undef max
 
// max和min非常简单了, 由于返回的是引用, 因此可以嵌套使用
template <class T>
inline const T& min(const T& a, const T& b)
{
  return b < a ? b : a;
}
 
template <class T>
inline const T& max(const T& a, const T& b)
{
  return  a < b ? b : a;
}
 
#endif /* __BORLANDC__ */
 
template <class T, class Compare>
inline const T& min(const T& a, const T& b, Compare comp)
{
  return comp(b, a) ? b : a;
}
 
template <class T, class Compare>
inline const T& max(const T& a, const T& b, Compare comp)
{
  return comp(a, b) ? b : a;
}
 
// 这是不支持随机访问的情况
template <class InputIterator, class OutputIterator>
inline OutputIterator __copy(InputIterator first, InputIterator last,
                             OutputIterator result, input_iterator_tag)
{
  // first != last导致要进行迭代器的比较, 效率低
  for ( ; first != last; ++result, ++first)
    *result = *first;
  return result;
}
 
template <class RandomAccessIterator, class OutputIterator, class Distance>
inline OutputIterator
__copy_d(RandomAccessIterator first, RandomAccessIterator last,
         OutputIterator result, Distance*)
{
  // 不进行迭代器间的比较, 直接指定循环次数, 高效
  for (Distance n = last - first; n > 0; --n, ++result, ++first)
    *result = *first;
  return result;
}
 
// 这是支持随机访问的情况
template <class RandomAccessIterator, class OutputIterator>
inline OutputIterator
__copy(RandomAccessIterator first, RandomAccessIterator last,
       OutputIterator result, random_access_iterator_tag)
{
  return __copy_d(first, last, result, distance_type(first));
}
 
template <class InputIterator, class OutputIterator>
struct __copy_dispatch
{
  // 这里是一个仿函数. 再次派发
  OutputIterator operator()(InputIterator first, InputIterator last,
                            OutputIterator result) {
    return __copy(first, last, result, iterator_category(first));
  }
};
 
// 提供兼容
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
 
// 可以直接移动, 不需要额外操作
template <class T>
inline T* __copy_t(const T* first, const T* last, T* result, __true_type)
{
  memmove(result, first, sizeof(T) * (last - first));
  return result + (last - first);
}
 
// 需要进行一些处理, 保证对象复制的正确性
template <class T>
inline T* __copy_t(const T* first, const T* last, T* result, __false_type)
{
  return __copy_d(first, last, result, (ptrdiff_t*) 0);
}
 
// 对指针提供特化
template <class T>
struct __copy_dispatch<T*, T*>
{
  T* operator()(T* first, T* last, T* result)
  {
    // 判断其内部是否具有trivial_assignment_operator, 以进行派发
    typedef typename __type_traits<T>::has_trivial_assignment_operator t;
    return __copy_t(first, last, result, t());
  }
};
 
template <class T>
struct __copy_dispatch<const T*, T*>
{
  T* operator()(const T* first, const T* last, T* result) {
    typedef typename __type_traits<T>::has_trivial_assignment_operator t;
    return __copy_t(first, last, result, t());
  }
};
 
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
 
// 将[first, last)拷贝到result处
template <class InputIterator, class OutputIterator>
inline OutputIterator copy(InputIterator first, InputIterator last,
                           OutputIterator result)
{
  // 此处进行函数派发操作
  return __copy_dispatch<InputIterator,OutputIterator>()(first, last, result);
}
 
// 针对char字符串的特化, 效率至上, C++的设计理念
inline char* copy(const char* first, const char* last, char* result)
{
  memmove(result, first, last - first);
  return result + (last - first);
}
 
// 针对wchar_t字符串的特化, 效率至上, C++的设计理念
inline wchar_t* copy(const wchar_t* first, const wchar_t* last,
                     wchar_t* result) {
  memmove(result, first, sizeof(wchar_t) * (last - first));
  return result + (last - first);
}
 
 
template <class BidirectionalIterator1, class BidirectionalIterator2>
inline BidirectionalIterator2 __copy_backward(BidirectionalIterator1 first,
                                              BidirectionalIterator1 last,
                                              BidirectionalIterator2 result)
{
  while (first != last) *--result = *--last;
  return result;
}
 
 
template <class BidirectionalIterator1, class BidirectionalIterator2>
struct __copy_backward_dispatch
{
  BidirectionalIterator2 operator()(BidirectionalIterator1 first,
                                    BidirectionalIterator1 last,
                                    BidirectionalIterator2 result)
  {
    return __copy_backward(first, last, result);
  }
};
 
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
 
template <class T>
inline T* __copy_backward_t(const T* first, const T* last, T* result,
                            __true_type)
{
  const ptrdiff_t N = last - first;
  memmove(result - N, first, sizeof(T) * N);
  return result - N;
}
 
template <class T>
inline T* __copy_backward_t(const T* first, const T* last, T* result,
                            __false_type)
{
  return __copy_backward(first, last, result);
}
 
template <class T>
struct __copy_backward_dispatch<T*, T*>
{
  T* operator()(T* first, T* last, T* result)
  {
    typedef typename __type_traits<T>::has_trivial_assignment_operator t;
    return __copy_backward_t(first, last, result, t());
  }
};
 
template <class T>
struct __copy_backward_dispatch<const T*, T*>
{
  T* operator()(const T* first, const T* last, T* result)
  {
    typedef typename __type_traits<T>::has_trivial_assignment_operator t;
    return __copy_backward_t(first, last, result, t());
  }
};
 
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
 
// 将[first, last)的元素反向拷贝到(..., last)处, 其机制和copy非常接近, 不做说明
template <class BidirectionalIterator1, class BidirectionalIterator2>
inline BidirectionalIterator2 copy_backward(BidirectionalIterator1 first,
                                            BidirectionalIterator1 last,
                                            BidirectionalIterator2 result)
{
  return __copy_backward_dispatch<BidirectionalIterator1,
                                  BidirectionalIterator2>()(first, last,
                                                            result);
}
 
 
template <class InputIterator, class Size, class OutputIterator>
pair<InputIterator, OutputIterator> __copy_n(InputIterator first, Size count,
                                             OutputIterator result,
                                             input_iterator_tag)
{
  for ( ; count > 0; --count, ++first, ++result)
    *result = *first;
  return pair<InputIterator, OutputIterator>(first, result);
}
 
template <class RandomAccessIterator, class Size, class OutputIterator>
inline pair<RandomAccessIterator, OutputIterator>
__copy_n(RandomAccessIterator first, Size count,
         OutputIterator result,
         random_access_iterator_tag)
{
  // 使用copy()以选择最高效的拷贝算法
  RandomAccessIterator last = first + count;
  return pair<RandomAccessIterator, OutputIterator>(last,
                                                    copy(first, last, result));
}
 
// 从first拷贝n个值到result处
template <class InputIterator, class Size, class OutputIterator>
inline pair<InputIterator, OutputIterator>
copy_n(InputIterator first, Size count,
       OutputIterator result)
{
  // 进行函数派发, 选咋高效版本
  return __copy_n(first, count, result, iterator_category(first));
}
 
// 使用value填充[first, last)区间
template <class ForwardIterator, class T>
void fill(ForwardIterator first, ForwardIterator last, const T& value)
{
  for ( ; first != last; ++first)
    *first = value;     // 调用的是operator =(), 这个要特别注意
}
 
// 用value填充[first, first + n)的区间
// 为了防止越界, 可以使用下面实例的技巧
// vector<int> vec();
// for (int i = 0; i < 10; ++i)
//      vec.push_back(i);
// fill_n(inserter(iv, iv.begin()), 100, 10);   // 这就可以使容器动态扩展
template <class OutputIterator, class Size, class T>
OutputIterator fill_n(OutputIterator first, Size n, const T& value)
{
  for ( ; n > 0; --n, ++first)
    *first = value;
  return first;
}
 
// 找到两个序列第一个失配的地方, 结果以pair返回
template <class InputIterator1, class InputIterator2>
pair<InputIterator1, InputIterator2> mismatch(InputIterator1 first1,
                          InputIterator1 last1,
                          InputIterator2 first2)
{
  // 遍历区间, 寻找失配点
  while (first1 != last1 && *first1 == *first2) {
    ++first1;
    ++first2;
  }
  return pair<InputIterator1, InputIterator2>(first1, first2);
}
 
// 提供用户自定义的二元判别式, 其余同上
template <class InputIterator1, class InputIterator2, class BinaryPredicate>
pair<InputIterator1, InputIterator2> mismatch(InputIterator1 first1,
                          InputIterator1 last1,
                          InputIterator2 first2,
                          BinaryPredicate binary_pred)
{
  while (first1 != last1 && binary_pred(*first1, *first2)) {
    ++first1;
    ++first2;
  }
  return pair<InputIterator1, InputIterator2>(first1, first2);
}
 
// 如果序列在[first, last)内相等, 则返回true, 如果第二个序列有多余的元素,
// 则不进行比较, 直接忽略. 如果第二个序列元素不足, 会导致未定义行为
template <class InputIterator1, class InputIterator2>
inline bool equal(InputIterator1 first1, InputIterator1 last1,
          InputIterator2 first2)
{
  for ( ; first1 != last1; ++first1, ++first2)
    if (*first1 != *first2)     // 只要有一个不相等就判定为false
      return false;
  return true;
}
 
// 进行比较的操作改为用户指定的二元判别式, 其余同上
template <class InputIterator1, class InputIterator2, class BinaryPredicate>
inline bool equal(InputIterator1 first1, InputIterator1 last1,
          InputIterator2 first2, BinaryPredicate binary_pred)
{
  for ( ; first1 != last1; ++first1, ++first2)
    if (!binary_pred(*first1, *first2))
      return false;
  return true;
}
 
// 字典序比较, 非常类似字符串的比较
// 具体比较方式参见STL文档, 另外strcmp()也可以参考
template <class InputIterator1, class InputIterator2>
bool lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
                 InputIterator2 first2, InputIterator2 last2)
{
  for ( ; first1 != last1 && first2 != last2; ++first1, ++first2) {
    if (*first1 < *first2)
      return true;
    if (*first2 < *first1)
      return false;
  }
  return first1 == last1 && first2 != last2;
}
 
// 二元判别式自己指定, 其余同上
template <class InputIterator1, class InputIterator2, class Compare>
bool lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
                 InputIterator2 first2, InputIterator2 last2,
                 Compare comp) {
  for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
  {
    if (comp(*first1, *first2))
      return true;
    if (comp(*first2, *first1))
      return false;
  }
  return first1 == last1 && first2 != last2;
}
 
// 针对字符串的特化, 效率至上
inline bool
lexicographical_compare(const unsigned char* first1,
                        const unsigned char* last1,
                        const unsigned char* first2,
                        const unsigned char* last2)
{
  const size_t len1 = last1 - first1;
  const size_t len2 = last2 - first2;
  const int result = memcmp(first1, first2, min(len1, len2));
  return result != 0 ? result < 0 : len1 < len2;
}
 
// 针对字符串的特化, 效率至上
inline bool lexicographical_compare(const char* first1, const char* last1,
                                    const char* first2, const char* last2)
{
#if CHAR_MAX == SCHAR_MAX
  return lexicographical_compare((const signed char*) first1,
                                 (const signed char*) last1,
                                 (const signed char*) first2,
                                 (const signed char*) last2);
#else
  return lexicographical_compare((const unsigned char*) first1,
                                 (const unsigned char*) last1,
                                 (const unsigned char*) first2,
                                 (const unsigned char*) last2);
#endif
}
 
// 一句话概括, 这个是strcmp()的泛化版本
template <class InputIterator1, class InputIterator2>
int lexicographical_compare_3way(InputIterator1 first1, InputIterator1 last1,
                                 InputIterator2 first2, InputIterator2 last2)
{
  while (first1 != last1 && first2 != last2) {
    if (*first1 < *first2) return -1;
    if (*first2 < *first1) return 1;
    ++first1; ++first2;
  }
  if (first2 == last2) {
    return !(first1 == last1);
  } else {
    return -1;
  }
}
 
// 特换版本, 效率决定一切
inline int
lexicographical_compare_3way(const unsigned char* first1,
                             const unsigned char* last1,
                             const unsigned char* first2,
                             const unsigned char* last2)
{
  const ptrdiff_t len1 = last1 - first1;
  const ptrdiff_t len2 = last2 - first2;
  const int result = memcmp(first1, first2, min(len1, len2));
  return result != 0 ? result : (len1 == len2 ? 0 : (len1 < len2 ? -1 : 1));
}
 
inline int lexicographical_compare_3way(const char* first1, const char* last1,
                                        const char* first2, const char* last2)
{
#if CHAR_MAX == SCHAR_MAX
  return lexicographical_compare_3way(
                (const signed char*) first1,
                                (const signed char*) last1,
                                (const signed char*) first2,
                                (const signed char*) last2);
#else
  return lexicographical_compare_3way((const unsigned char*) first1,
                                      (const unsigned char*) last1,
                                      (const unsigned char*) first2,
                                      (const unsigned char*) last2);
#endif
}
 
__STL_END_NAMESPACE
 
#endif /* __SGI_STL_INTERNAL_ALGOBASE_H */
 
// Local Variables:
// mode:C++
// End:

实例:

// swap algorithm example (C++11)
#include <iostream>     // std::cout
#include <utility>      // std::swap
 
int main () {
 
  int x=10, y=20;                  // x:10 y:20
  std::swap(x,y);                  // x:20 y:10
 
  int foo[4];                      // foo: ?  ?  ?  ?
  int bar[] = {10,20,30,40};       // foo: ?  ?  ?  ?    bar: 10 20 30 40
  std::swap(foo,bar);              // foo: 10 20 30 40   bar: ?  ?  ?  ?
 
  std::cout << "foo contains:";
  for (int i: foo) std::cout << ' ' << i;
  std::cout << '\n';
 
  return 0;
}

Output:
foo contains: 10 20 30 40

// fill algorithm example
#include <iostream>     // std::cout
#include <algorithm>    // std::fill
#include <vector>       // std::vector
 
int main () {
  std::vector<int> myvector (8);                       // myvector: 0 0 0 0 0 0 0 0
 
  std::fill (myvector.begin(),myvector.begin()+4,5);   // myvector: 5 5 5 5 0 0 0 0
  std::fill (myvector.begin()+3,myvector.end()-2,8);   // myvector: 5 5 5 8 8 8 0 0
 
  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';
 
  return 0;
}

Output:

myvector contains: 5 5 5 8 8 8 0 0


// fill_n example
#include <iostream>     // std::cout
#include <algorithm>    // std::fill_n
#include <vector>       // std::vector
 
int main () {
  std::vector<int> myvector (8,10);        // myvector: 10 10 10 10 10 10 10 10
 
  std::fill_n (myvector.begin(),4,20);     // myvector: 20 20 20 20 10 10 10 10
  std::fill_n (myvector.begin()+3,3,33);   // myvector: 20 20 20 33 33 33 10 10
 
  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';
 
  return 0;
}

Output:
myvector contains: 20 20 20 33 33 33 10 10


// equal algorithm example
#include <iostream>     // std::cout
#include <algorithm>    // std::equal
#include <vector>       // std::vector
 
bool mypredicate (int i, int j) {
  return (i==j);
}
 
int main () {
  int myints[] = {20,40,60,80,100};               //   myints: 20 40 60 80 100
  std::vector<int>myvector (myints,myints+5);     // myvector: 20 40 60 80 100
 
  // using default comparison:
  if ( std::equal (myvector.begin(), myvector.end(), myints) )
    std::cout << "The contents of both sequences are equal.\n";
  else
    std::cout << "The contents of both sequences differ.\n";
 
  myvector[3]=81;                                 // myvector: 20 40 60 81 100
 
  // using predicate comparison:
  if ( std::equal (myvector.begin(), myvector.end(), myints, mypredicate) )
    std::cout << "The contents of both sequences are equal.\n";
  else
    std::cout << "The contents of both sequences differ.\n";
 
  return 0;
}*/

武建豪在2020-05-16 22:11:05追加了内容

勿举报,那个代码只是示范

我要回答