c语言 输出一直为0 while循环求平均数

Question

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main() {
double a;
int x,z,b;
x = 0;
z = 0;
a = 0;
while (x != -1){
a += 1;
scanf("%d",&x);
z += x;
}
b = z / a;
printf("%f",b);

}

Answer 1

代码修正如下，输入数字时，最后以输入-1作为结束；b = (z1.0+1) / (a1.0-1)，z和a乘以1.0是为了整型转浮点，z加1是因为最后一次输入-1，被统计在z里面，a减一是将输入次数统计去掉最后输入-1这一次

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main() {
    double b;
    int x,z,a;
    x = 0;
    z = 0;
    a = 0;
    while (x != -1){
        a += 1;
        scanf("%d",&x);
        z += x;
    }
    b = (z*1.0+1) / (a*1.0-1);
    printf("%f",b);
}

验证结果如下：
3
3
3
-1
3.000000

3
4
3
-1
3.333333