POJ1679 The Unique MST[次小生成树]

//
//  main.cpp
//  poj1679
//
//  Created by Candy on 10/11/2016.
//  Copyright © 2016 Candy. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
const int N=105,M=10005,INF=1e9;
inline int read(){
    char c=getchar();int x=0,f=1;
    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}
    return x*f;
}
int n,m,u,v,w;
struct edge{
    int v,w,ne;
}e[N<<1];
int h[N],cnt=0;
inline void ins(int u,int v,int w){
    cnt++;
    e[cnt].v=v;e[cnt].w=w;e[cnt].ne=h[u];h[u]=cnt;
    cnt++;
    e[cnt].v=u;e[cnt].w=w;e[cnt].ne=h[v];h[v]=cnt;
}
struct data{
    int u,v,w;
    bool operator <(const data &r)const{return w<r.w;}
}a[M];
int fa[N];
inline int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
int use[N];
int kruskal(){
    sort(a+1,a+1+m);
    int cnt=0,ans=0;
    for(int i=1;i<=m;i++){
        int u=a[i].u,v=a[i].v,w=a[i].w;
        int f1=find(u),f2=find(v);
        if(f1==f2) continue;
        fa[f1]=f2;
        ins(u,v,w);
        use[i]=1;
        cnt++; ans+=w;
        if(cnt==n-1) break;
    }
    return ans;
}
int f[N][N],vis[N];
void dfs(int u){
    vis[u]=1;
    for(int i=h[u];i;i=e[i].ne){
        int v=e[i].v,w=e[i].w;
        if(vis[v]) continue;
        for(int x=1;x<=n;x++) if(vis[x]) f[x][v]=f[v][x]=max(f[x][u],w);
        dfs(v);
    }
}
void sol(){
    cnt=0;memset(h,0,sizeof(h));
    memset(f,0,sizeof(f));
    memset(vis,0,sizeof(vis));
    memset(use,0,sizeof(use));
    for(int i=1;i<=n;i++) fa[i]=i;
    
    int ans=kruskal();
    dfs(1);
    int mn=INF;
    for(int i=1;i<=m;i++) if(!use[i]){
        int u=a[i].u,v=a[i].v,w=a[i].w;//printf("hi %d %d %d  %d\n",u,v,w,f[u][v]);
        mn=min(mn,w-f[u][v]);
    }
    if(mn==0) puts("Not Unique!");
    else printf("%d\n",ans);
}
int main(int argc, const char * argv[]){
    int T=read();
    while(T--){
        n=read();m=read();
        for(int i=1;i<=m;i++){a[i].u=read();a[i].v=read();a[i].w=read();}
        sol();
    }
    return 0;
}