查找图上两个节点之间指定长度的所有可能路径

def find_paths(graph, start, end, length):
    paths = []
    dfs(graph, start, end, length, [start], paths)
    return paths

def dfs(graph, current, end, length, path, paths):
    if current == end and len(path) == length:
        paths.append(path[:])
        return

    if len(path) > length:
        return

    for neighbor in graph[current]:
        if neighbor not in path:
            path.append(neighbor)
            dfs(graph, neighbor, end, length, path, paths)
            path.pop()

# 示例图
graph = {
    'A': ['B', 'C'],
    'B': ['A', 'C', 'D'],
    'C': ['A', 'B', 'D', 'E'],
    'D': ['B', 'C', 'E', 'F'],
    'E': ['C', 'D'],
    'F': ['D']
}

start_node = 'A'
end_node = 'E'
target_length = 3

paths = find_paths(graph, start_node, end_node, target_length)

for path in paths:
    print(path)