import numpy as np

inf = float('inf')


def find_all_cycles(distances):
    num_nodes = distances.shape[0]
    visited = [False] * num_nodes
    cycles = []

    def dfs(node, start, path):
        visited[node] = True
        for neighbor in range(num_nodes):
            if distances[node, neighbor] != inf:
                if neighbor == start and len(path) > 1:
                    cycles.append(path + [start])
                elif not visited[neighbor]:
                    dfs(neighbor, start, path + [neighbor])
        visited[node] = False

    for start_node in range(num_nodes):
        dfs(start_node, start_node, [start_node])

    return cycles


distances = np.array([
    [inf, inf, 21, inf, 53],
    [inf, inf, 77, 84, 93],
    [21, 77, inf, inf, 53],
    [inf, 84, inf, inf, inf],
    [53, 93, 53, inf, inf]
])

all_cycles = find_all_cycles(distances)

if all_cycles:
    print("存在的回路路径为：")
    for cycle in all_cycles:
        print(cycle)
else:
    print("不存在回路")