K - The Unique MST

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mb5fe18e5a55d8d 2018-02-23 19:19:00

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K - The Unique MST

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
struct nond{
    int x,y,z;
}edge[101*101];
int T,N,M,x,y,z,fa[1000],num,ans[1000];
int tot,bns,k,answer=9999999;
int cmp(nond aa,nond bb){
    return aa.z<bb.z;
}
int find(int x){
    return fa[x]==x?x:fa[x]=find(fa[x]);
}
int main(){
    cin>>T;
    while(T--){
        cin>>N>>M;
        tot=0;bns=0;
        answer=9999999;
        memset(fa,0,sizeof(fa));
        memset(ans,0,sizeof(ans));
        for(int i=1;i<=M;i++){
            cin>>x>>y>>z;
            edge[i].x=x;
            edge[i].y=y;
            edge[i].z=z;
        }
        sort(edge+1,edge+1+M,cmp);
        for(int i=1;i<=N;i++)    fa[i]=i;
        for(int i=1;i<=M;i++){
            int dx=find(edge[i].x),dy=find(edge[i].y);
            if(dx!=dy){
                fa[dx]=dy;
                tot++;
                ans[tot]=i;
                bns+=edge[i].z;
            }
            if(tot==N-1)    break;
        }
        for(int i=1;i<=tot;i++){
            k=0;num=0;
            for(int j=1;j<=N;j++)    fa[j]=j;
            sort(edge+1,edge+1+M,cmp);
            for(int j=1;j<=M;j++){
                if(j==ans[i])    continue;
                int dx=find(edge[j].x),dy=find(edge[j].y);
                if(dx!=dy){
                    fa[dx]=dy;
                    num++;
                    k+=edge[j].z;
                }
                if(num==N-1)    break;
            }
            if(num==N-1) answer=min(k,answer);
        }
        if(answer==bns)    cout<<"Not Unique!"<<endl;
        else    cout<<bns<<endl;
    }
}