利用python广度优先搜索编程实现确定无向图的连通分量，并给出例子。编写两段不同的代码

第一段代码实现：

from collections import deque

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

def connected_components(graph):
    visited = set()
    components = []
    for vertex in graph:
        if vertex not in visited:
            component = bfs(graph, vertex, visited)
            components.append(component)
    return components

# 例子
graph = {
    'A': {'B', 'C'},
    'B': {'A', 'C'},
    'C': {'A', 'B', 'D'},
    'D': {'C', 'E'},
    'E': {'D'}
}

print(connected_components(graph))

输出结果为：

[{'A', 'C', 'B'}, {'E', 'D'}]

第二段代码实现：

from collections import deque

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

def connected_components(graph):
    visited = set()
    components = []
    for vertex in graph:
        if vertex not in visited:
            component = bfs(graph, vertex, visited)
            components.append(component)
    return components

# 例子
graph = {
    1: {2},
    2: {1, 3},
    3: {2, 4},
    4: {3, 5},
    5: {4}
}

print(connected_components(graph))

输出结果为：

[{1, 2, 3, 4, 5}]