使用C++写一个用蛮力法计算三维点云的最近两个点的距离的程序

以下是用C语言实现的蛮力法计算三维点云最近两个点距离的程序：

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

struct Point {
    double x, y, z;
};

double dist(struct Point a, struct Point b) {
    double dx = a.x - b.x;
    double dy = a.y - b.y;
    double dz = a.z - b.z;
    return sqrt(dx*dx + dy*dy + dz*dz);
}

double brute_force(struct Point points[], int n) {
    double min_dist = INFINITY;
    for (int i = 0; i < n; i++) {
        for (int j = i+1; j < n; j++) {
            double d = dist(points[i], points[j]);
            if (d < min_dist) {
                min_dist = d;
            }
        }
    }
    return min_dist;
}

int main() {
    // 读入点云数据
    int n;
    printf("请输入点云数量：");
    scanf("%d", &n);
    struct Point points[n];
    for (int i = 0; i < n; i++) {
        printf("请输入第%d个点的坐标(x y z)：", i+1);
        scanf("%lf %lf %lf", &points[i].x, &points[i].y, &points[i].z);
    }
    // 计算最近两点距离
    double min_dist = brute_force(points, n);
    printf("最近两点距离为：%.6lf\n", min_dist);
    return 0;
}

程序先读入点云数据，然后调用`brute_force`函数计算最近两个点的距离。`brute_force`函数使用两重循环枚举所有点对，并计算它们之间的距离，找到最小距离即可。`dist`函数计算两个点之间的欧几里得距离。最后程序输出最近两个点的距离。