杭电 1863 不正确

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;


public class Main{

	public static void main(String[] args) {
		
		Scanner in = new Scanner(System.in);
		
		//int dis[] = new int[n];//floyd算法不是单源最短路径的，所以不需要dis[]数组，我原先不理解
		while(in.hasNext()) {
			
			int road=in.nextInt();
			int village=in.nextInt();
			if(road==0) {
				break;
			}
			int graph[][] = new int[village][village];//*原来*号的这三行在while循环外面，是不对的，每次循环必须都是新的graph矩阵
			boolean used[] = new boolean[village];
			boolean roadused[][] = new boolean[village][village];
			for(int i=0;i<village;i++) {
				for(int j=0;j<village;j++) {
					if(i==j) {
						graph[i][j] =0;
						roadused[i][j] =true;
					}else {
						graph[i][j] = Integer.MAX_VALUE;
						roadused[i][j] = false;
					}
					
				}
			}
			
			for(int i=0;i<used.length;i++) {
				used[i]=false;
			}
		
		
			for(int i=0;i<road;i++) {
			
				int r=in.nextInt();
				int c=in.nextInt();
				int value = in.nextInt();

					if(value<graph[r-1][c-1])
						graph[r-1][c-1] = graph[c-1][r-1] =value;
			
			}
			int edgecount=0;
//			for(int i=0;i<graph.length;i++) {
//				for(int j=0;j<graph.length;j++) {
//					if(graph[i][j]!=Integer.MAX_VALUE) {
//						edgecount++;
//					}
//				}
//			}

			prim(graph,used,edgecount,roadused);
		
		}
		
		in.close();
		
	}
	
	public static void prim(int graph[][],boolean used[],int edgecount,boolean roadused[][]) {
		
		int count=0;//用于记录加入的点的数量
		ArrayList<Integer> list=new ArrayList<Integer>();
		int start=0;//默认把0首先加入Vnew集合
		int sum=0;
		list.add(0);
		used[0]=true;//原来没写这句
		while(list.size()!=graph.length) {

			int tempts=0;
			int tempti=0;
			int min=Integer.MAX_VALUE;
			Iterator it = list.iterator();
			while(it.hasNext()) {
				
				start=(int)it.next();
				System.out.println(start);
				for(int i=0;i<graph.length;i++) {//默认从0开始

					if(!used[i]&&!roadused[start][i]&&graph[start][i]!=Integer.MAX_VALUE) {

						//if(!used[i]&&!roadused[start][i]&&graph[start][i]!=Integer.MAX_VALUE&&!notin(i,list)) {
						if(min>graph[start][i]) {
							min=graph[start][i];
							tempts=start;
							tempti=i;
						}
					}
				}
				
			}
				roadused[tempts][tempti]=true;
				sum+=graph[tempts][tempti];
				list.add(tempti);
				count++;//原来没写这句
				System.out.println(count);
				used[tempti]=true;
			
		}
		if(count==used.length) {
			
			System.out.println(sum);
		}else {
			System.out.println("?");
		}
	}
	
//	public static boolean notin(int i,ArrayList<Integer> list) {
//		
//		Iterator it=list.iterator();
//		while(it.hasNext()) {
//			if((int)it.next()==i) {
//				return true;
//			}
//		}
//		
//		return false;
//	}
	
}