优先队列分支限界法求但单源最短路径Python

好的，关于优先队列分支限界法求单源最短路径的Python实现，可以参考以下代码：

import heapq

def dijkstra(graph, start):
    """
    Find shortest path to all nodes from the given start node
    using Dijkstra's algorithm with priority queue and branch
    and bound technique.

    :param graph: Graph structure represented as adjacency list
    :param start: Starting node
    :return: Shortest path to all nodes from the start node
    """
    # Initialize distances to all nodes as infinity except start node
    distances = {node: float('inf') for node in graph}
    distances[start] = 0

    # Initialize priority queue
    pq = [(0, start)]
    heapq.heapify(pq)

    while pq:
        # Get vertex with minimum known distance
        curr_dist, curr_vert = heapq.heappop(pq)

        # Ignore nodes whose distance is already determined
        if curr_dist > distances[curr_vert]:
            continue

        # Explore all edges outgoing from current vertex
        for adj_vert, edge_weight in graph[curr_vert].items():
            # Calculate new tentative distance to adjacent vertex
            tentative_dist = distances[curr_vert] + edge_weight

            # Update tentative distance if it's less than the already known distance
            if tentative_dist < distances[adj_vert]:
                distances[adj_vert] = tentative_dist
                heapq.heappush(pq, (tentative_dist, adj_vert))

    return distances

这个函数使用优先队列和分支限界技术实现了Dijkstra算法。它接受一个图结构的邻接列表和一个起始节点作为输入，并返回起始节点到所有节点的最短路径。

希望这个代码能够帮到你，如果你还有其他问题，可以继续问我哦！