【教程】dgl检查graph是否为连通图/是否存在不连接的多部分

import dgl
import torch

def get_connected_components(graph):
    visited = torch.zeros(graph.num_nodes(), dtype=torch.bool)
    components = []

    def bfs(node):
        queue = [node]
        component = []
        while queue:
            current = queue.pop(0)
            if not visited[current]:
                visited[current] = True
                component.append(current)
                neighbors = graph.successors(current).tolist() + graph.predecessors(current).tolist()
                queue.extend([n for n in neighbors if not visited[n]])
        return component

    for node in range(graph.num_nodes()):
        if not visited[node]:
            component = bfs(node)
            components.append(component)

    return components

# 示例用法
edges = ([0, 1, 2, 3, 5], [1, 2, 3, 4, 6])
graph = dgl.graph(edges)
components = get_connected_components(graph)

if len(components) == 1:
    print("The graph is connected.")
else:
    print(f"The graph is not connected. It has {len(components)} components.")
    print("Components:", components)

import dgl
import networkx as nx

def check_graph_connectivity(graph):
    # 将 DGL 图转换为 NetworkX 图
    nx_graph = graph.to_networkx().to_undirected()

    # 使用 NetworkX 检查连通性
    if nx.is_connected(nx_graph):
        print("The graph is connected.")
    else:
        connected_components = list(nx.connected_components(nx_graph))
        print(f"The graph is not connected. It has {len(connected_components)} components.")
        print("Sizes of each component:", [len(comp) for comp in connected_components])

# 示例用法
edges = ([0, 1, 2, 3, 5], [1, 2, 3, 4, 6])
graph = dgl.graph(edges)
check_graph_connectivity(graph)