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  1. import java.util.*;
  2.  
  3. public class Main {
  4.     public static void bfs(ArrayList<ArrayList<Integer>> graph, int start, int n) {
  5.         Queue<Integer> queue = new LinkedList<>();
  6.         boolean[] visited = new boolean[n + 1];
  7.         int[] level = new int[n + 1];
  8.  
  9.         queue.add(start);
  10.         visited[start] = true;
  11.         level[start] = 0;
  12.  
  13.         while (!queue.isEmpty()) {
  14.             int node = queue.poll();
  15.             System.out.println("Node: " + node + ", Level: " + level[node]);
  16.  
  17.             for (int neighbor : graph.get(node)) {
  18.                 if (!visited[neighbor]) {
  19.                     queue.add(neighbor);
  20.                     visited[neighbor] = true;
  21.                     level[neighbor] = level[node] + 1;
  22.                 }
  23.             }
  24.         }
  25.     }
  26.  
  27.     public static void main(String[] args) {
  28.         int n = 6, m = 5;
  29.         int[][] edges = {
  30.             {1, 2}, {1, 3}, {2, 4}, {2, 5}, {3, 6}
  31.         };
  32.  
  33.         ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
  34.         for (int i = 0; i <= n; i++) {
  35.             graph.add(new ArrayList<>());
  36.         }
  37.  
  38.         for (int[] edge : edges) {
  39.             int u = edge[0], v = edge[1];
  40.             graph.get(u).add(v);
  41.             graph.get(v).add(u);
  42.         }
  43.  
  44.         bfs(graph, 1, n);
  45.     }
  46. }
  47.  
Success #stdin #stdout 0.18s 55504KB
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Standard input is empty
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Node: 1, Level: 0
Node: 2, Level: 1
Node: 3, Level: 1
Node: 4, Level: 2
Node: 5, Level: 2
Node: 6, Level: 2
https://ideone.com/6HF5T4
language:
Java (HotSpot 12)
created:
282 days ago
visibility:
public

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