Wrong Answer
/in/foo.c: In function 'main':
/in/foo.c:8:10: warning: format '%f' expects argument of type 'float *', but argument 2 has type 'double *' [-Wformat=]
  scanf("%f",&x);
          ^
  代码
#include <stdio.h>
int main()
{
    double x;
	int y;
	printf("enter x.");
	scanf("%f",&x);
	if(x!=0)
	{
		if(x>0)
			y=1;
		else
			y=-1;
	}
	else 
		y=0;
	printf("x=%f,y=%d\n",x,y);
	return 0;
}