python实现迪杰斯特拉算法，并打印最短路径

在Python中，我们可以使用heapq库来实现Dijkstra算法，它可以帮助我们在查找最短路径时保持高效。以下是一个简单的例子，展示了如何找出从起始顶点到所有其他顶点的最短路径：

import heapq

def dijkstra(graph, start):
    distances = {node: float('infinity') for node in graph}
    distances[start] = 0
    queue = [(0, start)]  # 使用元组存储距离和节点

    while queue:
        current_distance, current_vertex = heapq.heappop(queue)

        if current_distance > distances[current_vertex]:
            continue  # 如果已经找到了更短的距离，跳过

        for neighbor, weight in graph[current_vertex].items():
            distance = current_distance + weight
            if distance < distances[neighbor]:
                distances[neighbor] = distance
                heapq.heappush(queue, (distance, neighbor))  # 更新队列

    return distances

# 假设graph是一个邻接权重字典，如 {(A: [B, C], B: [A, D], ...)}
graph = {...}

shortest_distances = dijkstra(graph, 'A')
print("从A出发的最短路径：")
for vertex, distance in shortest_distances.items():
    print(f"{vertex}: {distance}")