1012 数字分类 （20 分)

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
int main(){
    double sum4 = 0.0;
    int n, t, k = -1, cnt = 0, cnt2 = 0, max = 0, sum1 = 0, sum2 = 0, sum3 = 0;
    cin >> n;
    while (n--){
        cin >> t;
        if (t % 10 == 0)
            sum1 += t;
        else if (t % 5 == 1){
            k = -k;
            sum2 += t * k;
            cnt2++;  // 这个地方需要注意，若果没有这个计数器的话答案总是WA， 不知道为啥
        }
        else if (t % 5 == 2)
            sum3++;
        else if (t % 5 == 3){
            sum4 += t;
            cnt++;
        }
        else if (t % 5 == 4){
            if (max < t)
                max = t;
        }
    }
    if (cnt > 0) sum4 /= cnt;

    if (sum1 == 0) cout << "N" << ' ';
    else cout << sum1 << ' ';

    if (cnt2 == 0) cout << "N" << ' ';
    else cout << sum2 << ' ';

    if (sum3 == 0) cout << "N" << ' ';
    else cout << sum3 << ' ';

    if (sum4 == 0.0) cout << "N" << ' ';
    else cout << fixed << setprecision(1) << sum4 << ' ';

    if (max == 0) cout << "N" << endl;
    else cout << max << endl;

    return 0;
}