# -*- coding: utf-8 -*-
# Time : 2023/11/3 17:43
# Author : lirunsheng
# User : l'r's
# Software: PyCharm
# File : dfs.py

import numpy as np
def dfs_exists_path(distances):
    num_cities = distances.shape[0]
    visited = set()
    start_node = 0

    def dfs(node):
        visited.add(node)
        for neighbor in range(num_cities):
            if neighbor != node and neighbor not in visited and np.isfinite(distances[node, neighbor]):
                dfs(neighbor)

    dfs(start_node)

    return len(visited) == num_cities


def exists_path_without_inf(distances):
    # Check if there are any infinite distances
    if np.any(np.isinf(distances)):
        return False

    # Set the infinite distances to a large value
    max_distance = np.max(distances) + 1
    distances[np.isinf(distances)] = max_distance

    # Use DFS to check if there exists a path
    return dfs_exists_path(distances)


distances = np.array([
    [np.inf, 50, 99, np.inf, 64, np.inf],
    [50, np.inf, 12, 45, 74, 13],
    [99, 12, np.inf, 25, np.inf, 61],
    [np.inf, 45, 25, np.inf, 45, 47],
    [64, 74, np.inf, 45, np.inf, np.inf],
    [np.inf, 13, 61, 47, np.inf, np.inf]
])

print(exists_path_without_inf(distances))