How does the BFS algorithm work in Python?

Can you explain how the BFS algorithm works in Python?

Sure! BFS, or Breadth-First Search, is an algorithm for traversing or searching tree or graph data structures. It explores all the neighbor nodes at the present depth prior to moving on to nodes at the next depth level.

How do I implement BFS in Python?

You can implement BFS 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 kind of data structure is best for representing a graph?

Graphs can be represented using adjacency lists or adjacency matrices. Adjacency lists are more space-efficient for sparse graphs, while adjacency matrices are easier for dense graphs.