int find(int x,int y,int left,int right,node* a)
{
	int mid;
	if(left>right)
		return -1;
	mid = (left+right)/2;
	if(a[mid].x>x)
		find(x,y,left,mid-1,a);
	else if(a[mid].x<x)
		find(x,y,mid+1,right,a);
	else
	{
		if(a[mid].y>y)
			find(x,y,left,mid-1,a);
		else if(a[mid].y<y)
			find(x,y,mid+1,right,a);
		else
			return mid;
	}
}
在写二分的时候，原来是int find(double x,double y,int left,int right,node* a)，就是WA，后来改成了int find(int x,int y,int left,int right,node* a)，就AC了，跪求大神指出错误！！！