一个贪心算法，先排序，然后从小到大开始选边；
同时用并查集来维护两个点是否连通，如果当前边连接的两个点已经连通，那么说明选这条边没有任何意义，一定是劣的（因为前面已经排了序）
#include<bits/stdc++.h>
using namespace std;
const int N = 5005;
const int M = 2e5 + 5;
int n, m, f[N], ans;
struct Edge{int u, to, v;
}edge[M];
int find(int x){if(f[x] == x) return x;return f[x] = find(f[x]);
}
bool cmp(Edge a, Edge b){return a.v < b.v;
}
void kruskal(){int cnt = 0;sort(edge + 1, edge + 1 + m, cmp);for(int i = 1; i <= m; i++){int fu = find(edge[i].u);int ft = find(edge[i].to);if(fu == ft) continue;ans += edge[i].v;f[fu] = ft;cnt++;if(cnt == n-1) break;}if(cnt != n-1) ans = 0x3f3f3f3f;
}
int main(){cin >> n >> m;for(int i = 1; i <= m; i++){cin >> edge[i].u >> edge[i].to >> edge[i].v;}for(int i = 1; i <= n; i++) f[i] = i;kruskal();if(ans == 0x3f3f3f3f) cout << "orz";else cout << ans;return 0;
}