编辑代码

/* Online C Compiler and Editor */
#include <stdio.h>

int main()
{     
    int cur = 0, sum = 0, n = 0;

    printf("请输入（-1时退出循环）\n");
    scanf("%d", &cur);

    while(cur != -1) {            
        n++;        
        sum += cur;    
        printf("请输入（-1时退出循环）\n");
        scanf("%d", &cur);
    }

    if (n > 0) {        
        printf("%f", 1.0 * sum / n);
    }

    return 0;
}