问题标题: 酷町堂：3954

#include<iostream> 
using namespace std;
int main()
{
    int a;
    double b=0,c=0,d=0,e=0,f=0;
    cin>>a;
    while(a!=-1) 
    {
        cin>>a;
        if(a==-1)
        {
            break;
        }
        else if(a==3)
        {
            b++;
            e+=3;
        }
        else if(a==2)
        {
            c++;
            e+=2;
        }
        else if(a==0)
        {
            d++;
        }
        f++;
    }
    cout<<b<<" "<<c<<" "<<d;
    cout<<endl<<e<<" ";
    printf("%.1f",f/(a+2));
}