dijkstra(迪杰斯特拉)python

 学习笔记仅供参考......（希望对各位有帮助）

简单回顾一下

这里我就直接上代码，先过一遍代码

import heapq

MAX = float('inf')


def dijkstra(graph_matrix, start):
    # 图的顶点数
    num_vertices = len(graph_matrix)

    # 初始化距离列表，用于记录每个顶点到起始顶点的距离
    distances = [float('infinity')] * num_vertices
    #最开始自己和自己的距离当然为0啦
    distances[start] = 0

    # 使用优先队列（堆）来选择距离最短的顶点
    pq = [(0, start)]

    while pq:
        # 从堆中取出距离最短的顶点（用的是优先队列性质）
        current_distance, current_vertex = heapq.heappop(pq)

        # 如果当前距离大于当前顶点到起始顶点的距离，则跳过
        if current_distance > distances[current_vertex]:
            continue

        # 遍历当前顶点的相邻顶点
        for neighbor in range(num_vertices):
            # 如果有连接到相邻顶点的边，并且通过当前顶点到达相邻顶点的距离更短，则更新距离
            if graph_matrix[current_vertex][neighbor] != 0:
                distance = current_distance + graph_matrix[current_vertex][neighbor]
                if distance < distances[neighbor]:
                    distances[neighbor] = distance
                    heapq.heappush(pq, (distance, neighbor))

    return distances


# 示例二维列表表示的图
graph_matrix = [

    [0, 10, MAX, 4, MAX, MAX],
    [10, 0, 8, 2, 6, MAX],
    [MAX, 8, 10, 15, 1, 5],
    [4, 2, 15, 0, 6, MAX],
    [MAX, 6, 1, 6, 0, 12],
    [MAX, MAX, 5, MAX, 12, 0]
]

start_vertex = 0  # 从顶点0开始
distances = dijkstra(graph_matrix, start_vertex)
print("从顶点 {} 到其他顶点的最短距离：".format(start_vertex))
for vertex, distance in enumerate(distances):
    print("到顶点 {} 的最短距离为 {}".format(vertex, distance))
# [0, 6, 11, 4, 10, 16]
</