Can you explain breadth-first search in Python?

Can you explain breadth-first search in Python?

Sure! Breadth-first search (BFS) is an algorithm for traversing or searching tree or graph data structures. It starts at the root node and explores all of the neighbor nodes at the present depth prior to moving on to nodes at the next depth level.

How does BFS differ from depth-first search?

BFS explores all neighbors at the present depth before going deeper, while depth-first search goes as deep as possible down one branch before backtracking.

Can you show me a simple implementation of BFS in Python?

Absolutely! Here's a simple implementation:

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 kind of problems can BFS solve?

BFS is useful for finding the shortest path in unweighted graphs, solving puzzles like mazes, and in network broadcasting.