短路导航算法如何写代码

短路导航算法的代码实现可以采用Dijkstra算法或A*算法。

以下是使用Dijkstra算法实现短路导航算法的代码示例：

# 定义一个函数来计算最短路径
def dijkstra(graph, start, end):
    # 初始化距离字典和前驱节点字典
    distance = {vertex: float('inf') for vertex in graph}
    previous = {vertex: None for vertex in graph}

    # 设置起点的距离为0
    distance[start] = 0

    # 建立一个空的优先队列
    pq = []

    # 将起点加入优先队列
    heapq.heappush(pq, (0, start))

    # 开始遍历每个节点
    while pq:
        # 取出当前距离最小的节点
        current_distance, current_vertex = heapq.heappop(pq)

        # 如果当前节点已经被访问过，则跳过
        if current_distance > distance[current_vertex]:
            continue

        # 遍历当前节点的邻居节点
        for neighbor, weight in graph[current_vertex].items():
            # 计算到邻居节点的距离
            distance_to_neighbor = current_distance + weight

            # 如果当前距离比之前计算的距离更小，则更新距离和前驱节点
            if distance_to_neighbor < distance[neighbor]:
                distance[neighbor] = distance_to_neighbor
                previous[neighbor] = current_vertex
                heapq.heappush(pq, (distance_to_neighbor, neighbor))

    # 构建路径
    path = []
    vertex = end
    while vertex is not None:
        path.append(vertex)
        vertex = previous[vertex]

    # 将路径反转，得到正常的顺序
    path.reverse()

    return path, distance[end]

以上代码实现了使用Dijkstra算法计算最短路径的功能，其中输入参数graph是一个字典，存储了每个节点和它的邻居节点及对应的权重。start和end分别表示起点和终点。函数返回最短路径和对应的距离。