给我最短路径算法的代码

以下是 Dijkstra 算法的 Python 代码：

import heapq

def dijkstra(graph, start):
    distances = {node: float('inf') for node in graph}
    distances[start] = 0
    pq = [(0, start)]
    while pq:
        current_distance, current_node = heapq.heappop(pq)
        if current_distance > distances[current_node]:
            continue
        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

其中，`graph` 是一个字典，表示图的邻接表，`start` 是起点。算法的时间复杂度为 $O(E \log V)$，其中 $E$ 是边数，$V$ 是顶点数。