#include<stdio.h>
#include<stdlib.h>
int main()
{int x,y;
printf("输入x的值");
scanf("%d",&x);
if(x>0&&x<10) y=x+1;
else if(x=0) y=x-1;
else if(x>-5&&x<0) y=x;
printf("y=%d\n",y);
system("pause");}

if(x=0)
if(x==0)

要用两个等号==