问题标题: 酷町堂：7437 购物活动有效时间 90分

题目链接： 酷町堂：7437

各位大佬们帮忙看一下，这题卡了一星期

#include<bits/stdc++.h>

using namespace std;

int h1,m1,s1,h2,m2,s2,cnt;

long long x1,x2; char x;

int main(){

cin>>h1>>x>>m1>>x>>s1>>h2>>x>>m2>>x>>s2;

x1=h1*3600+m1*60+s1;

x2=h2*3600+m2*60+s2;

if(x2<=x1){

    cnt+=(86400-x1);

    cnt+=x2;

}else{

    cnt=h2-h1;

}

int a,b,c;

a=cnt/3600;

b=cnt/60%60;

c=cnt%60;

if(a<10){

     if(b<10){

        if(c<10){

             cout<<0<<a<<":"<<0<<b<<":"<<0<<c;

         }else{

             cout<<0<<a<<":"<<0<<b<<":"<<c;

        }

}else{

    cout<<0<<a<<":"<<b<<":"<<c;

} else if(b<10){

    if(c<10){

        cout<<a<<":"<<0<<b<<":"<<0<<c;

     }else{

        cout<<a<<":"<<0<<b<<":"<<c;

     }

}else if(c<10){

     cout<<a<<":"<<b<<":"<<0<<c;

}else{

    cout<<a<<":"<<b<<":"<<c;

} 

return 0;

}