规范化邻接列表

def build_normalized_adjacency_list(edges):
    adjacency_list = {}
    for u, v in edges:
        if u not in adjacency_list:
            adjacency_list[u] = []
        if v not in adjacency_list:
            adjacency_list[v] = []
        adjacency_list[u].append(v)
        adjacency_list[v].append(u)
    return adjacency_list

# 示例边集合
edges = [(1, 2), (2, 3), (3, 4), (4, 1)]
adj_list = build_normalized_adjacency_list(edges)
print(adj_list)

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

def build_normalized_adjacency_list_directed(edges):
    adjacency_list = {}
    for u, v in edges:
        if u not in adjacency_list:
            adjacency_list[u] = {'out': [], 'in': []}
        if v not in adjacency_list:
            adjacency_list[v] = {'out': [], 'in': []}
        adjacency_list[u]['out'].append(v)
        adjacency_list[v]['in'].append(u)
    return adjacency_list

# 示例边集合
edges = [(1, 2), (2, 3), (3, 4), (4, 1)]
adj_list_directed = build_normalized_adjacency_list_directed(edges)
print(adj_list_directed)

{1: {'out': [2], 'in': [4]}, 2: {'out': [3], 'in': [1]}, 3: {'out': [4], 'in': [2]}, 4: {'out': [1], 'in': [3]}}