
#include<stdio.h>
void main()
{
int x, y, z;
double a,b,c,d,average;
x = 1;
y = 1;
z = 0;
average = (x + y + z) / 3;
printf("第(1)类情况,输出结果为%lf\n", average);
printf("第(2)类情况,请继续依次输入x,y,z的值:");
scanf("%lf%lf%lf", &a, &b, &c);
d = (a + b + c) / 3;
printf("average=%.2lf", d);
}



