字符串中A的数量

计算字符串中元素个数用s.length()

#include <iostream>

using namespace std;

int main()
{
    string s;
    int n,coun = 0;
    cin>>s;
    n = s.length();
    for(int i = 0;i<n;i++){
        if(s[i] == 'A'){
            coun++;
        }
    }
    cout<<coun;
    return 0;
}