What are the implementations of BFS in different programming languages?

Can you explain how Breadth-First Search (BFS) works?

Sure! BFS is an algorithm for traversing or searching tree or graph data structures. It starts at the root node and explores all its neighbors at the present depth before moving on to nodes at the next depth level.

How is BFS implemented in Python?

In Python, BFS can be implemented using a queue. Here's a simple example:

from collections import deque

def bfs(graph, start):
    visited = set()
    queue = deque([start])

    while queue:
        vertex = queue.popleft()
        if vertex not in visited:
            visited.add(vertex)
            queue.extend(neighbor for neighbor in graph[vertex] if neighbor not in visited)
    return visited

What about in Java?

In Java, BFS can be implemented using a Queue as well. Here's a basic example:

import java.util.*;

public class BFS {
    public static void bfs(Map<Integer, List<Integer>> graph, int start) {
        Set<Integer> visited = new HashSet<>();
        Queue<Integer> queue = new LinkedList<>();
        queue.add(start);

        while (!queue.isEmpty()) {
            int vertex = queue.poll();
            if (!visited.contains(vertex)) {
                visited.add(vertex);
                queue.addAll(graph.get(vertex));
            }
        }
    }
}