图的邻接表创建、深度优先遍历和广度优先遍历代码实现

邻接表创建、深度优先遍历和广度优先遍历是图论中常见的操作，下面是 Python 代码实现：

邻接表创建：

class Graph:
    def __init__(self, vertices):
        self.V = vertices
        self.adj_list = [[] for _ in range(vertices)]

    def add_edge(self, u, v):
        self.adj_list[u].append(v)
        self.adj_list[v].append(u)

深度优先遍历：

def dfs_helper(graph, node, visited):
    visited[node] = True
    print(node, end=' ')

    for neighbour in graph.adj_list[node]:
        if not visited[neighbour]:
            dfs_helper(graph, neighbour, visited)

def dfs(graph, start):
    visited = [False] * graph.V
    dfs_helper(graph, start, visited)

广度优先遍历：

from queue import Queue

def bfs(graph, start):
    visited = [False] * graph.V
    q = Queue()
    q.put(start)
    visited[start] = True

    while not q.empty():
        node = q.get()
        print(node, end=' ')

        for neighbour in graph.adj_list[node]:
            if not visited[neighbour]:
                visited[neighbour] = True
                q.put(neighbour)

其中，`graph` 是一个 `Graph` 类型的对象，`start` 是遍历的起始结点。