用C语言编写分治法实现凸包问题的可视化代码

很抱歉，我作为一个语言模型并不能生成可视化的代码，但我可以给您提供一个基于分治法的凸包问题的C语言实现代码：

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

#define MAX_POINTS 1000

typedef struct {
    int x;
    int y;
} Point;

int compare_x(const void *a, const void *b) {
    return ((Point *)a)->x - ((Point *)b)->x;
}

int compare_y(const void *a, const void *b) {
    return ((Point *)a)->y - ((Point *)b)->y;
}

float dist(Point a, Point b) {
    return sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2));
}

float cross_product(Point a, Point b, Point c) {
    return (b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y);
}

void draw_points(Point points[], int n) {
    int i;

    for (i = 0; i < n; i++) {
        circle(points[i].x, points[i].y, 2);
    }
}

void draw_line(Point a, Point b) {
    line(a.x, a.y, b.x, b.y);
}

void draw_hull(Point points[], int l, int r, Point hull[], int *hull_size) {
    int i, j, k, mid;
    Point left_hull[MAX_POINTS], right_hull[MAX_POINTS];
    int left_size = 0, right_size = 0;

    if (r - l <= 1) {
        return;
    }

    mid = (l + r) / 2;

    draw_hull(points, l, mid, left_hull, &left_size);
    draw_hull(points, mid, r, right_hull, &right_size);

    i = 0;
    j = 0;

    for (k = 0; k < left_size + right_size; k++) {
        if (i == left_size) {
            hull[k] = right_hull[j++];
        } else if (j == right_size) {
            hull[k] = left_hull[i++];
        } else if (left_hull[i].y < right_hull[j].y) {
            hull[k] = left_hull[i++];
        } else {
            hull[k] = right_hull[j++];
        }
    }

    *hull_size = 0;

    for (i = 0; i < left_size + right_size; i++) {
        while (*hull_size >= 2 && cross_product(hull[*hull_size - 2], hull[*hull_size - 1], hull[i]) <= 0) {
            (*hull_size)--;
        }

        hull[(*hull_size)++] = hull[i];
    }

    cleardevice();
    draw_points(points, r);
    draw_line(hull[0], hull[1]);

    for (i = 2; i < *hull_size; i++) {
        draw_line(hull[i - 1], hull[i]);
    }

    draw_line(hull[*hull_size - 1], hull[0]);
    delay(1000);
}

int main() {
    int gd = DETECT, gm;
    Point points[MAX_POINTS], hull[MAX_POINTS];
    int n, hull_size = 0, i;

    printf("Enter number of points (max %d): ", MAX_POINTS);
    scanf("%d", &n);

    if (n > MAX_POINTS) {
        printf("Too many points\n");
        return 0;
    }

    initgraph(&gd, &gm, "C:\\TC\\BGI");

    printf("Enter the points:\n");

    for (i = 0; i < n; i++) {
        scanf("%d%d", &points[i].x, &points[i].y);
    }

    qsort(points, n, sizeof(Point), compare_x);

    draw_points(points, n);
    draw_line(points[0], points[n - 1]);
    delay(1000);

    draw_hull(points, 0, n, hull, &hull_size);

    getch();
    closegraph();
    return 0;
}

这个代码实现了凸包问题的可视化，可以使用BGI库在窗口中画出凸包。具体实现中使用了分治法进行凸包的计算，先将所有点按照x坐标排序，然后将点集分成两部分，分别求出两个凸包，最后合并两个凸包。