C语言判断一个点与圆的位置关系

C语言判断一个点与圆的位置关系

#include <stdio.h>

typedef struct
{
	float x;
	float y;
}POINT;

int main(int argc, char *argv[])
{
	float lfv_rad;
	float lfv_dis;
	int liv_quit = 0;
	POINT lsv_point1, lsv_point2;

	printf("请输入圆心的坐标：\n");
	scanf("%f,%f", &lsv_point1.x, &lsv_point1.y);
	printf("请输入圆的半径\n");
	scanf("%f", &lfv_rad);

	printf("圆心为(%0.2f,%0.2f),半径为%0.2f的圆已经确定\n", lsv_point1.x, lsv_point1.y, lfv_rad);

	printf("现在请输入需要判断的坐标:\n");
	scanf("%f,%f", &lsv_point2.x, &lsv_point2.y);
	lfv_dis = (lsv_point2.x - lsv_point1.x) * (lsv_point2.x - lsv_point1.x) + (lsv_point2.y - lsv_point1.y) * (lsv_point2.y - lsv_point1.y);

	if(lfv_dis == (lfv_rad * lfv_rad))
	{
		printf("在圆上\n");
	}
	else if(lfv_dis >= (lfv_rad * lfv_rad))
	{
		printf("在圆外\n");
	}
	else 
	{
		printf("在园内\n");
	}
	return 0;
}

结果：

C语言编程学习笔记