poj1861最小生成树

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <climits>

#include <string>

#include <iostream>

#include <map>

#include <cstdlib>

#include <list>

#include <set>

#include <queue>

#include <stack>



using namespace std;

int father[22222];

int getfather(int x)

{

    if(x!=father[x])

        return father[x]=getfather(father[x]);

    return father[x];

}

struct Node

{

    int a;int b;int c;

}node[111111];

int cmp(const Node&a,const Node &b)

{

    return a.c<b.c;

}

int Max(int a,int b)

{

    return a>b?a:b;

}

int gg[111111];

int Map[1111][1111];

int main()

{

    int n,m;

    while(~scanf("%d%d",&n,&m)){

        int ans=0;

        int sum=0;

        memset(Map,0,sizeof(Map));

        for(int i=1;i<=n;i++) father[i]=i;

        for(int i=0;i<m;i++){

            int a,b,c;

            scanf("%d%d%d",&a,&b,&c);

            if(!Map[a][b]){

                Map[a][b]=Map[b][a]=c;

                node[ans].a=a;node[ans].b=b;node[ans++].c=c;

            }

            if(Map[a][b]&&Map[a][b]>c){

                Map[a][b]=Map[b][a]=c;

                node[ans].a=a;node[ans].b=b;node[ans++].c=c;

            }

        }

        sort(node,node+ans,cmp);

       // cout<<endl;

      //  for(int i=0;i<n;i++)

        //    printf("%d %d %d\n",node[i].a,node[i].b,node[i].c);

        int cc=0;

        int ret=0;

        for(int i=0;i<ans;i++){

            int fa=getfather(node[i].a);int fb=getfather(node[i].b);

            if(fa!=fb){

                father[fa]=fb;ret=Max(ret,node[i].c);

                gg[cc++]=i;

            }

        }

        cout<<ret<<endl;

        cout<<cc<<endl;

        for(int i=0;i<cc;i++){

            printf("%d %d\n",node[gg[i]].a,node[gg[i]].b);

        }

    }

    return 0;

}