数的深度广度优先遍历

import java.util.Queue;
import java.util.concurrent.LinkedBlockingQueue;

class TreeNode{
    int item;
    TreeNode left;
    TreeNode right;
}

public class test1 {

    public static void walkDeep(TreeNode treeNode){
        System.out.println(treeNode.item);
        if(treeNode.left != null){
            walkDeep(treeNode.left);
        }
        if(treeNode.right != null){
            walkDeep(treeNode.right);
        }
    }

    public static void walkWide(TreeNode treeNode){
        Queue<TreeNode> queue = new LinkedBlockingQueue<TreeNode>();
        queue.add(treeNode);
        while (!queue.isEmpty()){
            TreeNode temp = queue.poll();
            System.out.println(temp.item);
            if(temp.left != null) queue.add(temp.left);
            if(temp.right != null) queue.add(temp.right);

        }
    }

    public static void main(String args[]){
        TreeNode root = new TreeNode();
        root.item = 0;

        TreeNode c1 = new TreeNode();
        c1.item = 1;


        TreeNode c2 = new TreeNode();
        c2.item = 2;


        TreeNode c3 = new TreeNode();
        c3.item = 3;

        TreeNode c4 = new TreeNode();
        c4.item = 4;

        c1.left = c3;
        c1.right = c4;
        root.left = c1;
        root.right = c2;
        walkDeep(root);
        System.out.println("----");
        walkWide(root);
    }
}