dijkstra算法python实现

Dijkstra算法可以用来求最短路径。在Python中可以使用堆数据结构来实现。具体实现可以参考以下代码：

import heapq

def dijkstra(graph, start):
    distances = {vertex: float('infinity') for vertex in graph}
    distances[start] = 0
    priority_queue = [(0, start)]
    while priority_queue:
        current_distance, current_vertex = heapq.heappop(priority_queue)
        if current_distance > distances[current_vertex]:
            continue
        for neighbor, weight in graph[current_vertex].items():
            distance = current_distance + weight
            if distance < distances[neighbor]:
                distances[neighbor] = distance
                heapq.heappush(priority_queue, (distance, neighbor))
    return distances

在上述代码中，“graph”是邻接表表示的图，“start”是起点。算法会返回一个字典，表示每个顶点到起点的最短距离。