MST_Kruskal

#include<iostream>

#include<fstream>#include<algorithm>using namespace std;struct Tline{int a,b,len;}Line[10005];int fa[10005];int n,m,ans=0;bool _cmp(Tline a,Tline b){return a.len<b.len;}int u_f(int x){int root = x;while (fa[root]!=root) root=fa[root];while (fa[x]!=x) { int y = fa[x]; fa[x] = root; x = y;}return root;}int main(){cin >> n >> m;for (int i=0;i<n;i++) fa[i]=i;for (int i=0;i<m;i++) cin >> Line[i].a >> Line[i].b >> Line[i].len;sort(Line,Line+m,_cmp);for (int i=0;i<m&&n>0;i++){int f_a=u_f(Line[i].a),f_b=u_f(Line[i].b);if (f_a!=f_b){n--;fa[f_a]=f_b;ans+=Line[i].len;}}if (n>0) cout << "No Answer!!\n";else cout << ans;}