次小生成树

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
#define N 101
struct Edge
{
    int x,y,z;
}edge[2*N];
int t,x,y,flag,ans,ans2,n,m,num2;
int far[N];
bool path[2*N];
void set()
{
    for(int i=1;i<=n;i++)
    far[i]=i;
}
void unionn(int x,int y)
{
    far[x]=y;
}
int f(int x)
{
    far[x]==x?x:far[x]=f(far[x]);
}
bool cmp(Edge a,Edge b)
{
    return a.x<b.y;
}
void kruskal()
{
    set();
    int num1=0;
    sort(edge+1,edge+m+1,cmp);
    for(int i=1;i<=m;i++)
    {
        int fx=f(edge[i].x),fy=f(edge[i].y);
        if(fx!=fy)
        {
            unionn(fx,fy);
            ans+=edge[i].z;
            path[++num1]=i;
        }
        if(num1==n-1)
        break;
    }
    
    for(int k=1;k<=num1;k++)
    {
    set();
        ans2=0;num2=0;
        for(int i=1;i<=m;i++)
        {
            if(i==path[i])
            continue;
            int fx=f(edge[i].x),fy=f(edge[i].y);
            if(fx!=fy)
            {
                unionn(fx,fy);
                ans2+=edge[i].z;
                num2++;
            }
            if(num2==n-1&&ans2==ans)flag=1;
        }
    }
}

int main()
{
    scanf("%d",&t);
    while(t--)
    {
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    scanf("%d%d%d",&edge[i].x,&edge[i].y,&edge[i].z);
    flag=0;
    ans=0;
    kruskal();
    if(flag)
    printf("Not Unique!\n");
    else
    printf("%d\n",ans);
    }
    return 0;
}