平面三点定圆心 c语言代码

以下是一个用C语言实现的平面三点定圆心的代码示例：

#include <stdio.h>
#include <math.h>

struct Point {
    double x;
    double y;
};

struct Circle {
    struct Point center;
    double radius;
};

struct Circle calculateCircle(struct Point p1, struct Point p2, struct Point p3) {
    struct Circle circle;

    // 计算中垂线的斜率
    double slope1 = (p2.y - p1.y) / (p2.x - p1.x);
    double slope2 = (p3.y - p2.y) / (p3.x - p2.x);
    
    // 计算中垂线的中点坐标
    double midX = (slope1 * slope2 * (p1.y - p3.y) + slope2 * (p1.x + p2.x) - slope1 * (p2.x + p3.x)) / (2 * (slope2 - slope1));
    double midY = -1 * (midX - (p1.x + p2.x) / 2) / slope1 + (p1.y + p2.y) / 2;
    
    // 计算圆心坐标和半径
    circle.center.x = midX;
    circle.center.y = midY;
    circle.radius = sqrt(pow(p1.x - midX, 2) + pow(p1.y - midY, 2));
    
    return circle;
}

int main() {
    struct Point p1, p2, p3;
    struct Circle circle;
    
    printf("请输入三个点的坐标：\n");
    printf("点1的x坐标：");
    scanf("%lf", &p1.x);
    printf("点1的y坐标：");
    scanf("%lf", &p1.y);
    printf("点2的x坐标：");
    scanf("%lf", &p2.x);
    printf("点2的y坐标：");
    scanf("%lf", &p2.y);
    printf("点3的x坐标：");
    scanf("%lf", &p3.x);
    printf("点3的y坐标：");
    scanf("%lf", &p3.y);
    
    circle = calculateCircle(p1, p2, p3);
    
    printf("圆心坐标：(%lf, %lf)\n", circle.center.x, circle.center.y);
    printf("圆的半径：%lf\n", circle.radius);
    
    return 0;
}

这段代码通过输入三个点的坐标，计算出通过这三个点的圆的圆心坐标和半径。请注意，代码中使用了结构体来表示点和圆，方便进行数据的存储和传递。