PTA 7-10 统计均分

#include<stdio.h>
int main()
{
    int x,sum=0,y=0;
    while(1)
    {
        scanf("%d",&x);
        if(x==0)
            break;
        if(x<0)
            continue;
        sum=sum+x;
        y=y+1;
    }
    printf("%.2f",1.0*sum/y);
}