CSP2018_12_4

package practiceofcsp;

import java.util.Arrays;
import java.util.Scanner;

public class CSP2018_12_4_me {
	static int pre[];//存贮根节点
	static int find(int x) {//寻找根节点
		if(pre[x]==x) {
			return x;
		}
		else {
			return pre[x]=find(pre[x]);
		}
	}
	static boolean iscircle(int x,int y) {//x和y连接是否能构成环
		if(find(x)==find(y)) {
			return false; 
		}
		else {
			return true;
		}
	}
	static void islink(int x,int y) {//注意是根连接
		int xx=find(x);
		int yy=find(y);
		pre[yy]=xx;
	}
	public static void main(String[] args) {
		
		Scanner input = new Scanner(System.in);
		int n = input.nextInt();
		int m = input.nextInt();
		int root = input.nextInt();
		pre = new int[n+1];
		for(int i=0;i<pre.length;i++) {
			pre[i]=i;
		}
		Edge edge[]=new Edge[m];
		
		
		for(int i=0;i<edge.length;i++) {
			edge[i]=new Edge();
			edge[i].from=input.nextInt();
			edge[i].to=input.nextInt();
			edge[i].time=input.nextInt();
		}
		int count =0;
		Arrays.sort(edge);
		int max=0;
		for(int i=0;i<edge.length&&count<n-1;i++) {
			Edge edgei=new Edge();
			edgei=edge[i];
			if(iscircle(edgei.from,edgei.to)){
				islink(edgei.from,edgei.to);
				count++;
				max=edgei.time;
			}
		}
		System.out.println(max);
	}
}
class Edge implements Comparable<Edge>{
	int from;
	int to;
	int time;
	@Override
	public int compareTo(Edge o) {
		// TODO Auto-generated method stub
		return time-o.time;
	}
	
}