solving.py 文件源码

def shortest_path(graph, source, target):
    """Return the windowed shortest path between source and target
    in the given graph.

    Graph is expected to be a dict {node: {successors}}.

    Return value is a tuple of 2-tuple, each 2-tuple representing a
    window of size 2 on the path.

    """
    if source == target: return tuple()  # no move needed
    nxg = nx.Graph()
    for node, succs in graph.items():
        for succ in succs:
            nxg.add_edge(node, succ)
    return tuple(nx.dijkstra_path(nxg, source, target))