二叉树深度优先遍历

import java.util.ArrayList;
import java.util.List;


public class BinaryTreeTraverse {


    static class BinTree {
        public BinTree left;
        public BinTree right;
        public BinTree root;
        //    数据域
        private Object data;
        //    存节点
        public List<BinTree> datas;


        public BinTree(BinTree left, BinTree right, Object data) {
            this.left = left;
            this.right = right;
            this.data = data;
        }


        //    将初始的左右孩子值为空
        public BinTree(Object data) {
            this(null, null, data);
        }


        public BinTree() {
        }


        public void createTree(Object[] objs) {
            datas = new ArrayList<BinTree>();
            // 将一个数组的值依次转换为Node节点
            for (Object o : objs) {
                datas.add(new BinTree(o));
            }
            // 第一个数为根节点
            root = datas.get(0);
            // 建立二叉树
            for (int i = 0; i < objs.length / 2; i++) {
                //左孩子
                datas.get(i).left = datas.get(i * 2 + 1);
                // 右孩子
                if (i * 2 + 2 < datas.size()) {//避免偶数的时候 下标越界
                    datas.get(i).right = datas.get(i * 2 + 2);
                }
            }
        }


        //先序遍历
        public void preOrder(BinTree root) {


            if (root != null) {
                System.out.print(root.data + " ");
                preOrder(root.left);
                preOrder(root.right);
            }
        }


        //中序遍历
        public void inOrder(BinTree root) {


            if (root != null) {
                inOrder(root.left);
                System.out.print(root.data+ " ");
                inOrder(root.right);
            }
        }


        //后序遍历
        public void afterOrder(BinTree root) {


            if (root != null) {
                afterOrder(root.left);
                afterOrder(root.right);
                System.out.print(root.data+ " ");
            }
        }


    }


    public static void main(String[] args) {
        BinTree BinTree = new BinTree();
        Object[] a = {0,1, 2, 3, 4, 5, 6};
        BinTree.createTree(a);


        System.out.print("先序遍历：");
        BinTree.preOrder(BinTree.root);
        System.out.println();


        System.out.print("中序遍历：");
        BinTree.inOrder(BinTree.root);
        System.out.println();


        System.out.print("后序遍历：");
        BinTree.afterOrder(BinTree.root);
    }


}

先序遍历：0 1 3 4 2 5 6 
中序遍历：3 1 4 0 5 2 6 
后序遍历：3 4 1 5 6 2 0