ccf 201703 4

//并查集 克鲁斯卡尔
#include <iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int maxv=100000+5;
const int maxe=200000+5;
struct Edge{
int from,to,weight;
};
bool operator<(const Edge &E1,const Edge &E2)
{
    return E1.weight<E2.weight;
}
Edge edges[maxe];
int parent[maxv];
int find(int x)
{
    return x==parent[x]?x:parent[x]=find(parent[x]);
}
int main()
{
    int n,m;
    scanf("%d%d",&n,&m);
        for(int i=1;i<=n;i++)
            {
                parent[i]=i;                //并查集初始化
            }
        int v1,v2,cost;
        for(int i=0;i<m;i++)
        {
            scanf("%d%d%d",&v1,&v2,&cost);
            edges[i].from=v1;
            edges[i].to=v2;
            edges[i].weight=cost;
        }
        sort(edges,edges+m);
        int sum=0;
        for(int i=0;i<m;i++)
        {
            if(find(1)==find(n)) break;
            int p1=find(edges[i].from);
            int p2=find(edges[i].to);
            if(p1==p2) continue;
            parent[p1]=p2;
            sum=max(sum,edges[i].weight);
        }
    printf("%d\n",sum);
    return 0;
}