How do I implement BFS and DFS algorithms in Python?

How do I implement BFS and DFS algorithms in Python?

To implement BFS (Breadth-First Search) and DFS (Depth-First Search) in Python, you can use a graph represented as an adjacency list. Would you like to see code examples for both?

Yes, please show me the code for both algorithms.

Sure! Here's a simple implementation:

from collections import deque

# BFS implementation

def bfs(graph, start):
    visited = set()
    queue = deque([start])
    while queue:
        vertex = queue.popleft()
        if vertex not in visited:
            visited.add(vertex)
            queue.extend(graph[vertex] - visited)
    return visited

# DFS implementation

def dfs(graph, start, visited=None):
    if visited is None:
        visited = set()
    visited.add(start)
    for neighbor in graph[start] - visited:
        dfs(graph, neighbor, visited)
    return visited

Would you like an explanation of how these algorithms work?

Yes, that would be great!

BFS explores all neighbors at the present depth prior to moving on to nodes at the next depth level, using a queue. DFS, on the other hand, explores as far as possible along each branch before backtracking, using recursion or a stack. Let me know if you need more details!