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  1. import java.util.*;
  2. import java.io.*;
  3.  
  4. class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         int t = sc.nextInt();
  8.  
  9.         while (t-- > 0) {
  10.             int n = sc.nextInt();
  11.             int e = sc.nextInt();
  12.  
  13.             List<List<Integer>> adj=new ArrayList<>();
  14.             for(int i=0;i<=n;i++)
  15.             adj.add(new ArrayList<>());
  16.  
  17.  
  18.             for (int k = 0; k < e; k++) {
  19.                 int u = sc.nextInt();
  20.                 int v = sc.nextInt();
  21.                 adj.get(u).add(v);
  22.                 adj.get(v).add(u);
  23.             }
  24.  
  25.             int visited[]=new int[n+1];
  26.             int level[]=new int[n+1];
  27.             Queue<Integer> q=new LinkedList<>();
  28.  
  29.             q.add(1);
  30.             visited[1]=1;
  31.             level[1]=0;
  32.  
  33.  
  34.             while(!q.isEmpty())
  35.             {
  36.             	int temp=q.poll();
  37.             	System.out.print(temp+" ");
  38.             	for(int neighbour:adj.get(temp))
  39.             	{
  40.             		if(visited[neighbour]==0)
  41.             		{
  42.             			q.add(neighbour);
  43.             			visited[neighbour]=1;
  44.             			level[neighbour]=level[temp]+1;
  45.             		}
  46.             	}
  47.  
  48.             }
  49.             System.out.println();
  50.  
  51.             for(int i=1;i<=n;i++)
  52.             {
  53.             	if(visited[i]==0)
  54.             	System.out.println("we cant reach the source node to "+i);
  55.             	else
  56.             		System.out.println("we can reach the source node to "+i);
  57.  
  58.             }
  59.  
  60.         }
  61.     }
  62. }
Success #stdin #stdout 0.17s 60912KB
comments (?)
stdin 
1
6 4
1 2
1 3
4 5
5 6
stdout 
1 2 3 
we can reach the source node to 1
we can reach the source node to 2
we can reach the source node to 3
we cant reach the source node to 4
we cant reach the source node to 5
we cant reach the source node to 6
https://ideone.com/1EaKvO
language:
Java (HotSpot 12)
created:
4 days ago
visibility:
public

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