dijkstra-python实现

import heapq

def dijkstra(graph, start):
    # 初始化距离字典：所有节点距离设为无穷大，起点为0
    distances = {node: float('inf') for node in graph}
    distances[start] = 0
    
    # 优先队列（最小堆），存储(当前距离, 节点)元组
    priority_queue = [(0, start)]
    
    while priority_queue:
        # 弹出当前距离最小的节点
        current_distance, current_node = heapq.heappop(priority_queue)
        
        # 若当前距离已大于已知最短距离，跳过（避免重复处理）
        if current_distance > distances[current_node]:
            continue
        
        # 遍历当前节点的邻居
        for neighbor, weight in graph[current_node].items():
            distance = current_distance + weight
            
            # 若找到更短路径，更新距离并加入队列
            if distance < distances[neighbor]:
                distances[neighbor] = distance
                heapq.heappush(priority_queue, (distance, neighbor))
    
    return distances