题解 | #记负均正#

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

int main()
{
    int n;
    while (cin >> n) {
        double negCount = 0, posCount = 0;
        double sum = 0;
        for (int i = 0;i < n;i++) {
            double m;
            cin >> m;
            if (m < 0) {
                negCount++;
            } else if (m > 0) {
                posCount++;
                sum += m;
            }
        }
    
        if (posCount == 0) {
            cout << negCount << " " << fixed << setprecision(1) << 0.0 << endl;
            continue;
        }

        double flt = sum / posCount;
        cout << negCount << " " << fixed << setprecision(1) << flt << endl;
    }
}