The Unique MST

#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <queue>
const int INF=0x3f3f3f3f;
using namespace std;
const int M=110;
int n,m;
vector<int> v[M];
int G[M][M];
struct Node
{
    int u,v;
    int w;
};
Node node[100000+10];
char vis[M][M];
bool cmp(Node a,Node b)
{
    return a.w<b.w;
}
int p[M];
int f(int x)
{
    return p[x]==x?x:p[x]=f(p[x]);
}
int MST()   // kruskal build a new Graph by vector v.
{
    int w=0;
    for(int i=0; i<n; i++) v[i].clear();
    for(int i=0; i<n; i++)
    {
        p[i]=i;
    }
    sort(node,node+m,cmp);
    for(int i=0; i<m; i++)
    {
        if(f(node[i].u) != f(node[i].v))
        {
            p[f(node[i].u)] = f(node[i].v);
            w+=node[i].w;
            v[node[i].u].push_back(node[i].v);
            v[node[i].v].push_back(node[i].u);
            vis[node[i].u][node[i].v]=1;
            vis[node[i].v][node[i].u]=1;
        }
    }
    return w;
}

int Max[M][M];
int viss[M];
queue<int>q;
void BFS(int s)   //BFS make the Max(u,v) means the max key of the path u->v in the MST.
{
    memset(viss,0,sizeof(viss));
    q.push(s);
    viss[s]=1;
    while(!q.empty())
    {
        int temp = q.front();
        q.pop();
        for(int i=0; i<v[temp].size(); i++)
        {
            if(!viss[v[temp][i]] && !Max[v[temp][i]][s])
            {
                q.push(v[temp][i]);
                viss[v[temp][i]]=1;
                Max[s][v[temp][i]] = Max[v[temp][i]][s] = max(G[temp][v[temp][i]],Max[s][temp]);
            }
        }
    }
}

int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        memset(vis,0,sizeof(vis));
        memset(Max,0,sizeof(Max));
        memset(G,0,sizeof(G));
        scanf("%d %d",&n,&m);
        for(int i=0; i<m; i++)
        {
            scanf("%d %d %d",&node[i].u,&node[i].v,&node[i].w);
            node[i].u-=1;
            node[i].v-=1;
            G[node[i].u][node[i].v] = node[i].w;
            G[node[i].v][node[i].u] = node[i].w;
        }
        int ans1 = MST();
        for(int i=0; i<n; i++)
        {
            BFS(i);
        }
        int ans2=INF;
        for(int i=0; i<n; i++)
        {
            for(int j=0; j<n; j++)
            {
                if(!vis[i][j] && G[i][j])
                {
                    ans2 = min(ans2,ans1+G[i][j]-Max[i][j]);
                }
            }
        }
        if(ans1 == ans2)
        {
            printf("Not Unique!\n");
        }
        else
        {
            printf("%d\n",ans1);
        }
    }
    return 0;
}