求输入几个数的平均值

#include <stdio.h>main (){    int x;    double sum=0,aver;    int i=0;    scanf ("%d",&x);    while (x!=-1)    {        sum+=x;        i++;        scanf ("%d",&x);    }    if(i>0)    {        aver=sum/i;        printf("%.3f\n",aver);    }}

知识点:1、while语句格式[scanf(); while(a!=b) {scanf();}]