迪杰斯特拉（Dijkstra）最短路径算法

import heapq

def dijkstra(graph, start):
    # 初始化距离字典和已访问节点集合
    distances = {node: float('infinity') for node in graph}
    distances[start] = 0
    visited = set()
    
    # 使用最小堆来存储待访问节点及其距离
    pq = [(0, start)]
    
    while pq:
        # 弹出距离最小的节点
        current_distance, current_node = heapq.heappop(pq)
        
        # 如果节点已访问，则跳过
        if current_node in visited:
            continue
        
        visited.add(current_node)
        
        # 更新邻居节点的距离
        for neighbor, weight in graph[current_node].items():
            distance = current_distance + weight
            if distance < distances[neighbor]:
                distances[neighbor] = distance
                heapq.heappush(pq, (distance, neighbor))
    
    return distances