洛谷P2330 [SCOI2005]繁忙的都市 题解 最小生成树的最长边

题目链接：https://www.luogu.com.cn/problem/P2330

这道题其实就是求最小生成树的最长边。

实现代码如下：

#include <bits/stdc++.h>
using namespace std;
const int maxn = 10010, maxm = 100010;
int n, m, f[maxn], a[maxn];
struct Edge {
    int u, v, w;
} edge[maxm];
bool cmp(Edge a, Edge b) {
    return a.w < b.w;
}
void init() {
    for (int i = 1; i <= n; i ++) f[i] = i;
}
int Find(int x) {
    return x == f[x] ? x : f[x] = Find(f[x]);
}
void Union(int x, int y) {
    int a = Find(x), b = Find(y);
    f[a] = f[b] = f[x] = f[y] = min(a, b);
}
void solve() {
    init();
    cout << n-1 << " ";
    int cnt = 0;
    for (int i = 0; i < m; i ++) {
        int u = edge[i].u, v = edge[i].v;
        if (Find(u) != Find(v)) {
            Union(u, v);
            cnt ++;
            if (cnt == n-1) {
                cout << edge[i].w << endl;
                break;
            }
        }
    }
}
int main() {
    cin >> n >> m;
    for (int i = 0; i < m; i ++) cin >> edge[i].u >> edge[i].v >> edge[i].w;
    sort(edge, edge+m, cmp);
    solve();
    return 0;
}