图

无向图的节点定义如下：

Java

// 无向图的节点
class UndirectedGraphNode {
    int label;
    ArrayList<UndirectedGraphNode> neighbors;
    UndirectedGraphNode(int x) { label = x;}
};

C++

// 无向图的节点
struct UndirectedGraphNode {
    int label;
    vector<UndirectedGraphNode *> neighbors;
    UndirectedGraphNode(int x) : label(x) {};
};