题解 | #记负均正#

#include <bits/stdc++.h>
#include <iomanip>
using namespace std;

int main() {
    int n;
    cin >> n;
    int count = 0;
    int count2 = 0;
    int sum = 0;
    float mean = 0.0;
    int num;
    while(cin >> num){
        if(num < 0) count += 1;
        else if(num > 0) {sum += num;count2 += 1;}
    }
    if(count2 == 0) {mean = 0.0;cout << count << " ";printf("%.1f",mean);}
    else{mean = sum/static_cast<float>(count2);cout << count << " ";printf("%.1f",mean);}
    return 0;
}
// 64 位输出请用 printf("%lld")