4041424344454647484950515253545556575859606162

import java.util.*;

class Solution {
    // Function to perform BFS traversal from node 0
    public List<Integer> bfsOfGraph(int V, List<List<Integer>> adj) {
        List<Integer> bfs = new ArrayList<>(); // List to store BFS traversal
        boolean[] vis = new boolean[V];        // Visited array initialized to false
        Queue<Integer> q = new LinkedList<>(); // Queue for BFS

        // Start BFS from node 0
        q.add(0);
        vis[0] = true;

        while (!q.isEmpty()) {
            // Dequeue a node from the queue
            int node = q.poll();
            bfs.add(node); // Add it to BFS result

            // Traverse all adjacent/unvisited neighbors
            for (int neighbor : adj.get(node)) {
                if (!vis[neighbor]) {
                    q.add(neighbor);      // Enqueue neighbor
                    vis[neighbor] = true; // Mark neighbor as visited
                }
            }
        }

        return bfs;
    }

    // Helper function to add an undirected edge between u and v
    public void addEdge(List<List<Integer>> adj, int u, int v) {
        adj.get(u).add(v);
        adj.get(v).add(u);
    }

    // Helper to print the BFS result
    public void printAns(List<Integer> ans) {
        for (int num : ans) {
            System.out.print(num + " ");
        }
    }

    public static void main(String[] args) {
        // Create adjacency list for 5 nodes
        List<List<Integer>> adj = new ArrayList<>();
        for (int i = 0; i < 5; i++) adj.add(new ArrayList<>());

        Solution obj = new Solution();

        // Add edges to the graph
        obj.addEdge(adj, 0, 1);
        obj.addEdge(adj, 0, 2);
        obj.addEdge(adj, 0, 3);
        obj.addEdge(adj, 2, 4);

        // Perform BFS and print result
        List<Integer> ans = obj.bfsOfGraph(5, adj);
        obj.printAns(ans);
    }
}

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from collections import deque

class Solution:
    def bfsOfGraph(self, V, adj):
        bfs = []                  # List to store BFS result
        vis = [False] * V         # Visited array initialized to False
        q = deque()               # Queue for BFS

        # Start BFS from node 0
        q.append(0)
        vis[0] = True

        while q:
            node = q.popleft()    # Dequeue node
            bfs.append(node)      # Add node to result

            # Visit all unvisited neighbors
            for neighbor in adj[node]:
                if not vis[neighbor]:
                    q.append(neighbor)    # Enqueue neighbor
                    vis[neighbor] = True  # Mark neighbor as visited

        return bfs

# Function to add undirected edge between u and v
def addEdge(adj, u, v):
    adj[u].append(v)
    adj[v].append(u)

# Function to print BFS result