数据结构Java版之深度优先-图（十二）

package mygraph;

import java.util.Stack;

public class DFS_Vertex {
　　 //创建一个我们需要的节点类
    class Vertex {
        private char lable;
        private int val;
        private boolean wasvisited;
        Vertex(char lable) {
            this.lable = lable;
        }
        Vertex() {
            
        }
    }
    private char lable; // 矩阵元素
    private Vertex[][] list = new Vertex[20][20];
    private Vertex[] vertexList = new Vertex[20];
    private int nVerts; // 当前顶点下标
    DFS_Vertex() {
        this.nVerts = 0;
        for(int i = 0; i < 20; i ++) {
            for(int j = 0; j < 20; j ++) {
                list[i][j] = new Vertex();
            }
        }
    }

    // 增加一个顶点
    public void addVertex(char lable) {
        vertexList[nVerts++] = new Vertex(lable);
    }

    // 增加一条边
    public void addEdge(int start, int end) {
        list[start][end].val = 1;
        list[end][start].val = 1;
    }

    // 打印矩阵
    public void printMatrix() {
        for (int i = 0; i < nVerts; i++) {
            for (int j = 0; j < nVerts; j++) {
                System.out.print(list[i][j].val);
            }
            System.out.println();
        }
    }
    //显示字符
    public void showVertex(int v) {
        System.out.print(vertexList[v].lable + "\t");
    }
    //获得邻接未访问节点
    public int getAdjUnvisitedVertex(int v) {
        for(int j = 0; j < nVerts; j ++) {
            if((list[v][j].val == 1) && (vertexList[j].wasvisited == false)) {
                return j;
            }
        }
        return -1;
    }
    //DFS
    public void DFS() {
        Stack<Integer> s = new Stack();
        vertexList[0].wasvisited = true;
        showVertex(0);
        s.push(0);
        int v;
        while(s.size() > 0) {
            v = getAdjUnvisitedVertex(s.peek());
            if(v == -1) {
                s.pop();
            }else {
                vertexList[v].wasvisited = true;
                showVertex(v);
                s.push(v);
            }
        }
        for(int j = 0; j < nVerts; j ++) {
            vertexList[j].wasvisited = false;
        }
    }

}

    public static void main(String[] args) {
        DFS_Vertex ds = new DFS_Vertex();
        ds.addVertex(‘A‘);    //0
        ds.addVertex(‘B‘);    //1
        ds.addVertex(‘C‘);    //2    
        ds.addVertex(‘D‘);    //3
        ds.addVertex(‘E‘);    //4
        ds.addEdge(0, 1);    //A-B 
        ds.addEdge(0, 3);    //A-D
        ds.addEdge(1, 4);    //B-E
        ds.addEdge(3, 4);    //D-E
        ds.addEdge(4, 2);    //E-C
        ds.printMatrix();
        ds.DFS();
    }

10001
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10001
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A    B    E    C    D