源代码：

/*
3 2
10 10
10 0
30 0
*/
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
using namespace std;
struct Node
{
    int x, y;
} node[501];
struct Edge
{
    int from, to;
    double dis;
} edge[1300], minedge[1300];
double getdis(Node &a, Node &b)
{
    int disx = abs(a.x - b.x), disy = abs(a.y - b.y);
    return sqrt(disx * disx + disy * disy);
}
bool cmp(Edge &a, Edge &b)
{
    return a.dis < b.dis;
}
int fa[501];
int find(int &x)
{
    return fa[x] == x ? x : fa[x] = find(x);
}
bool merge(int &x,int &y)
{
    int fx = find(x), fy = find(y);
    if (fa[fx] == fy)
        return true;
    fa[fx] = fy;
    return false;
}
int n, k;
int main()
{
    ios::sync_with_stdio(false);
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> node[i].x >> node[i].y;
    //建立边
    int cnt = 0;
    
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= i; j++)
        {
            if (i == j)
                continue;
            edge[cnt].from = i;
            edge[cnt].to = j;
            edge[cnt].dis = getdis(node[i], node[j]);
            cnt++;
        }
    
    //kruskal
    int cnt1 = 0;
    double sum = 0;
    sort(edge, edge+cnt, cmp);
    for (int i = 0; i < cnt; i++)
        if (!merge(edge[i].from, edge[i].to))
        {
            
            sum += edge[i].dis;
            minedge[cnt1++] = edge[i];
        }
    
    sort(minedge, minedge+cnt1, cmp);
    cnt1--;
    while (k--)
    {
        sum -= minedge[cnt1].dis;
        cnt1--;
    }
    cout << fixed << setprecision(2) << sum;
    return 0;
}

控制台：

3 2
10 10
10 0
30 0
zsh: segmentation fault xxx

怎么办啊！！！