用C语言,输入某个点A的平面坐标(下,有),判断(输出)A点是在圆内,圆外还是在圆周上,其中圆心坐标为(2,2),半径为1.
时间: 2023-06-13 17:08:10 浏览: 91
以下是用C语言实现的代码:
```c
#include <stdio.h>
#include <math.h>
int main()
{
float x, y; // 点A的x、y坐标
float cx = 2.0, cy = 2.0; // 圆心坐标
float r = 1.0; // 圆的半径
float distance; // 点A与圆心的距离
printf("请输入点A的平面坐标(x, y):");
scanf("%f, %f", &x, &y);
// 计算点A与圆心的距离
distance = sqrt(pow(x - cx, 2) + pow(y - cy, 2));
if (distance < r) {
printf("点A在圆内\n");
}
else if (distance == r) {
printf("点A在圆周上\n");
}
else {
printf("点A在圆外\n");
}
return 0;
}
```
首先,我们定义了点A的x、y坐标、圆心坐标cx、cy和圆的半径r,然后通过scanf函数输入点A的坐标。接着,我们使用sqrt函数和pow函数计算点A与圆心的距离distance。最后,根据距离的大小判断点A在圆内、圆周上还是圆外,并输出相应的信息。
相关问题
任意给出平面上n个点的坐标,试求覆盖这n个点的圆的最小半径。写C语言程序
以下是使用C语言实现Welzl算法求解最小圆覆盖问题的代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#define MAX_POINTS 1000
struct Point {
double x, y;
};
struct Circle {
struct Point center;
double radius;
};
double distance(struct Point a, struct Point b) {
double dx = a.x - b.x;
double dy = a.y - b.y;
return sqrt(dx*dx + dy*dy);
}
struct Circle circle_from_points(struct Point a, struct Point b) {
struct Circle circle;
circle.center.x = (a.x + b.x) / 2;
circle.center.y = (a.y + b.y) / 2;
circle.radius = distance(a, b) / 2;
return circle;
}
struct Circle circle_from_points_3(struct Point a, struct Point b, struct Point c) {
double A = a.x - b.x;
double B = a.y - b.y;
double C = a.x - c.x;
double D = a.y - c.y;
double E = A*(a.x + b.x) + B*(a.y + b.y);
double F = C*(a.x + c.x) + D*(a.y + c.y);
double G = 2*(A*(c.y - b.y) - B*(c.x - b.x));
if (G == 0) {
struct Circle circle = { {0, 0}, INFINITY };
return circle;
}
double center_x = (D*E - B*F) / G;
double center_y = (A*F - C*E) / G;
struct Point center = { center_x, center_y };
double radius = distance(center, a);
struct Circle circle = { center, radius };
return circle;
}
struct Circle circle_from_points_bounding(struct Point* points, int n, struct Point p) {
struct Circle circle = { p, 0 };
for (int i = 0; i < n; i++) {
if (distance(circle.center, points[i]) > circle.radius) {
if (circle.center.x == p.x && circle.center.y == p.y) {
circle = circle_from_points(points[i], p);
} else {
circle = circle_from_points_3(points[i], p, points[(i+1)%n]);
}
}
}
return circle;
}
struct Circle welzl(struct Point* points, struct Point* boundary, int n, int b) {
struct Circle circle = { {0, 0}, INFINITY };
if (b == 3) {
circle = circle_from_points_3(boundary[0], boundary[1], boundary[2]);
} else if (n == 0 && b == 2) {
circle = circle_from_points(boundary[0], boundary[1]);
} else if (n == 1 && b == 1) {
circle.center = points[0];
circle.radius = 0;
} else if (n == 0 && b == 1) {
circle.center = boundary[0];
circle.radius = 0;
} else {
n--;
struct Circle d = welzl(points+1, boundary, n, b);
if (distance(d.center, points[0]) > d.radius) {
boundary[b++] = points[0];
circle = welzl(points+1, boundary, n, b-1);
b--;
} else {
circle = d;
}
}
return circle;
}
struct Circle min_circle(struct Point* points, int n) {
struct Point boundary[3];
srand(time(NULL));
for (int i = 0; i < 3; i++) {
boundary[i] = points[i];
}
return welzl(points+3, boundary, n-3, 3);
}
int main() {
int n;
printf("Enter the number of points: ");
scanf("%d", &n);
struct Point points[MAX_POINTS];
printf("Enter the coordinates of the points:\n");
for (int i = 0; i < n; i++) {
scanf("%lf %lf", &points[i].x, &points[i].y);
}
struct Circle circle = min_circle(points, n);
printf("Minimum circle: center = (%.2lf, %.2lf), radius = %.2lf\n", circle.center.x, circle.center.y, circle.radius);
return 0;
}
```
注意,该程序假设输入的点集中至少有三个点,且不会进行输入校验。
声明一个表示平面中点坐标的结构体类型,然后输入三个点的坐标,判断这三点是否能构成三角形,若能构成,求出三边的边长。用c语言给出完整代码
在 C 语言中,可以使用结构体来表示平面中点的坐标。结构体可以看作是一种用户定义的类型,它可以包含多个变量,每个变量可以是不同的类型。
下面是声明一个表示平面中点坐标的结构体类型的代码:
```
struct Point {
double x;
double y;
};
```
然后,我们可以定义三个点的坐标,判断这三点是否能构成三角形,若能构成,求出三边的边长。
```
#include <stdio.h>
#include <math.h>
struct Point {
double x;
double y;
};
// 计算两点之间的距离
double distance(struct Point p1, struct Point p2) {
return sqrt((p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y));
}
int main(void) {
// 定义三个点
struct Point p1 = {1, 1};
struct Point p2 = {2, 2};
struct Point p3 = {3, 3};
// 计算三条边的长度
double a = distance(p1, p2);
double b = distance(p2, p3);
double c = distance(p3, p1);
// 判断是否能构成三角形
if (a + b > c && a + c > b && b + c > a) {
printf("能构成三角形\n");
} else {
printf("不能构成三角形\n");
}
return 0;
}
```
在上面的代码中,我们首先声明了一个表示平面中点坐标的结构体类型,然后定义了三个点的坐标。接下来
相关推荐
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![application/pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)