C语言实现直线和圆弧关于y = 35直线对称，示例代码

下面是使用C语言实现直线和圆弧关于y=35直线对称的示例代码：

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

// 定义点结构体
typedef struct point {
    double x;
    double y;
} Point;

// 计算点关于y=35直线对称的点
Point symmetric_point(Point p, Point sym) {
    Point p_sym;
    double k = (p.y - sym.y) / (p.x - sym.x);
    double b = p.y - k * p.x;
    double x_sym = (-2 * k * b + sym.x * (1 + k * k) + 2 * k * sym.y) / (1 + k * k);
    double y_sym = k * x_sym + b;
    p_sym.x = x_sym;
    p_sym.y = y_sym;
    return p_sym;
}

// 计算圆弧关于y=35直线对称的圆弧
void symmetric_arc(Point center, double radius, Point sym) {
    double distance = fabs(center.y - sym.y);
    if (distance == radius) {
        // 如果圆弧与y=35直线相切，则对称后的圆弧仍然与y=35直线相切
        printf("The symmetric arc is still tangent to y=35.\n");
    } else if (distance < radius) {
        // 如果圆弧在y=35直线下方，则对称后的圆弧在y=35直线上方
        double new_center_y = center.y + 2 * (35 - center.y);
        double new_radius = sqrt(radius * radius - distance * distance);
        printf("The symmetric arc is centered at (%.2lf, %.2lf) and has radius %.2lf.\n",
               center.x, new_center_y, new_radius);
    } else {
        // 如果圆弧在y=35直线上方，则对称后的圆弧在y=35直线下方
        printf("The symmetric arc does not intersect with y=35.\n");
    }
}

int main() {
    // 直线上的两个点
    Point p1 = {10, 20};
    Point p2 = {30, 40};
    // 计算它们关于y=35直线对称的点
    Point p1_sym = symmetric_point(p1, (Point) {0, 35});
    Point p2_sym = symmetric_point(p2, (Point) {0, 35});
    // 输出对称点的坐标
    printf("The symmetric point of (%.2lf, %.2lf) is (%.2lf, %.2lf).\n",
           p1.x, p1.y, p1_sym.x, p1_sym.y);
    printf("The symmetric point of (%.2lf, %.2lf) is (%.2lf, %.2lf).\n",
           p2.x, p2.y, p2_sym.x, p2_sym.y);

    // 圆弧的圆心和半径
    Point center = {15, 20};
    double radius = 10;
    // 计算圆弧关于y=35直线对称的圆弧
    symmetric_arc(center, radius, (Point) {0, 35});

    return 0;
}

这段代码定义了一个`Point`结构体表示二维坐标点，实现了`symmetric_point`函数计算点关于y=35直线对称的点，以及`symmetric_arc`函数计算圆弧关于y=35直线对称的圆弧。在`main`函数中，我们定义了一个直线上的两个点和一个圆弧的圆心和半径，分别计算它们关于y=35直线对称的点和对称圆弧，并输出结果。