常见错误，把"=="写成"="了
#include "stdio.h"main(){float x,y;scanf("%f",&x);if(x>0&&x<5) y=x*x+1;else if(x==0) y=0; //这里是x==0else if(x>-5&&x<0) y=4-x;printf("x=%0.2f,y=%0.2f\n",x,y);}
