题解 | #记负均正#

#include <stdio.h>
#include <math.h>

int main() 
{
    int n = 0;
    int arr[2000] = {0};
    while (scanf("%d", &n) != EOF) 
    {
        int i = 0;
        int count = 0;
        int counint = 0;
        float num = 0;

        for (i = 0; i < n; i++) 
        {
            scanf("%d", arr + i);
            if (arr[i] < 0) {
                count++;
            }
            if (arr[i] > 0) {
                num += arr[i];
                counint++;
            }
        }
        printf("%d %0.1f", count, num/counint > 0 ?num / counint:0);
    }
    return 0;
}

num/counint > 0 ?num / counint:0 解决无法确定数。