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59 lines
1.4 KiB
59 lines
1.4 KiB
#include <bits/stdc++.h>
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using namespace std;
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const int N = 110, M = 210;
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const int INF = 0x3f3f3f3f;
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int n, m; // n条顶点,m条边
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int res; // 最小生成树的权值和
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int cnt; // 最小生成树的结点数
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// Kruskal用到的结构体
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struct Node {
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int a, b, c;
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bool const operator<(const Node &t) const {
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return c < t.c; // 边权小的在前
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}
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} edge[M]; // 数组长度为是边数
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// 并查集
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int p[N];
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int find(int x) {
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if (p[x] != x) p[x] = find(p[x]);
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return p[x];
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}
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// Kruskal算法
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int kruskal() {
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// 1、按边权由小到大排序
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sort(edge, edge + m);
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// 2、并查集初始化
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for (int i = 1; i <= n; i++) p[i] = i;
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// 3、迭代m次
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for (int i = 0; i < m; i++) {
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int a = edge[i].a, b = edge[i].b, c = edge[i].c;
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a = find(a), b = find(b);
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if (a != b)
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p[a] = b, res += c, cnt++; // cnt是指已经连接上边的数量
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}
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// 4、特判是不是不连通
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if (cnt < n - 1) return INF;
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return res;
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}
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int main() {
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cin >> n >> m;
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int sum = 0;
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// Kruskal算法直接记录结构体
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for (int i = 0; i < m; i++) {
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int a, b, c;
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cin >> a >> b >> c;
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edge[i] = {a, b, c};
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sum += c;
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}
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int t = kruskal();
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printf("%d\n", sum - t);
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return 0;
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}
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