Java数据结构：图

在写图算法题目时候，题目有各种各样的方式表现成一个图，这种数据结构记录用java 的对象封装成一个实现类，在以后调用时直接用

public class Graph {
    //节点
    public HashMap nodes;
    //边
    public HashSet edges;
    public Graph(){
        nodes = new HashMap<>();
        edges = new HashSet<>();
    }
}

public class Edge {
    //边的权重
    public int weight;
    //边的起点
    public Node from;
    //边的终点
    public Node to;
    public Edge(int weight , Node from , Node to){
        this.weight = weight;
        this.from = from;
        this.to = to ;
    }
}

public class Node {
    //图的值
    public int value ;
    //有向图 出入度有关系
    //无向图 出入度无关系
    //入度
    public int in ;
    //出度
    public int out ;
    //该节点的邻居节点
    public ArrayList nexts;
    //该节点所连接的边
    public ArrayList edges;
    public Node(int value){
        this.value = value;
        in = 0 ;
        out = 0 ;
        nexts = new ArrayList<>();
        edges = new ArrayList<>();
    }
}