kruskal最小生成树模板

这里记录kruskal算法的模板，防止以后忘记。

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

//这个需要kruskal算法和并查集
struct edge {
	int x, y, t;
};
vector<int> fa;

int find(int x) {
	return fa[x] == x ? x : (fa[x] = find(fa[x]));
}
int main() {
	int n, m;
	cin >> n >> m;
	vector<edge> road(m);
	int ans = 0;
	fa = vector<int>(n + 1);
	for (int i = 0; i < m; i++) {
		cin >> road[i].x >> road[i].y >> road[i].t;
	}
	sort(road.begin(), road.end(), [](edge a, edge b) {
		return a.t < b.t;
		});
	int cnt = n; //有n个连通块
	for (int i = 0; i <= n; i++) {
		fa[i] = i;
	}
	for (int i = 0; i < m; i++) {
		int fx = find(road[i].x);
		int fy = find(road[i].y);
		if (fx != fy) {
			fa[fx] = fy;
			ans += road[i].t;
			cnt--;
		}
		if (cnt == 1) {
			break;
		}
	}
	if (cnt != 1) {
		cout << "orz" << endl;
		return 0;
	}
	cout << ans;
	return 0;
}