通过中序前序遍历重构二叉树层次结构

import java.awt.print.Printable;
import java.util.LinkedList;
import java.util.Queue;

 
public class RestoreBinaryTreeByTwoTraverseOder {  
    //  
    // ===binary tree===   
    //      1  
    //   
    //     2 3  
    //   
    //   4 5 6 7  
    //   
    //  8   
        // ===binary tree===  
    //   
    // preorder traversal: 12485367; inorder traversal : 84251637;  
    //   
    // input : Preoder & inoder traversal results of a binary tree(e.g. above)  
    // output : The orginal binary tree  
    //  
    public Node restore(int[] preorder, int[] inorder) {  
        if (preorder.length == 0 ||  inorder.length == 0) {  
            return null;  
        }  
        Node root = new Node(preorder[0]);  
        int rootIndexInInorder = findIndexByValue(preorder[0], inorder);  
        int lengthOfSubPreorder1 = rootIndexInInorder;  
        int[] subPreorder1 = {};  

        if (lengthOfSubPreorder1 > 0) {  
            // generate subPreorder1 2485  
            subPreorder1 = new int[lengthOfSubPreorder1];  
            System  
                    .arraycopy(preorder, 1, subPreorder1, 0,  
                            lengthOfSubPreorder1);  
        }  
        // remain subPreorder  
        int lengthOfSubPreorder2 = preorder.length - lengthOfSubPreorder1 - 1;  
        int[] subPreorder2 = {};  
        if (lengthOfSubPreorder2 > 0) {  
            // generate subPreorder2 367  
            subPreorder2 = new int[lengthOfSubPreorder2];  
            System.arraycopy(preorder, preorder.length  
                    - lengthOfSubPreorder2, subPreorder2, 0, lengthOfSubPreorder2);  
        }  
  
        int lengthOfSubinorder1 = rootIndexInInorder;  
        int[] subinorder1 = {};  
        if (lengthOfSubinorder1 > 0) {  
            subinorder1 = new int[lengthOfSubinorder1];  
            // generate subPreorder1 8425  
            System.arraycopy(inorder, 0, subinorder1, 0, lengthOfSubinorder1);  
        }  
        // remain subInorder  
        int lengthOfSubInorder2 = preorder.length - lengthOfSubinorder1 - 1;  
        int[] subinorder2 = {};  
        if (lengthOfSubInorder2 > 0) {  
            subinorder2 = new int[lengthOfSubInorder2];  
            // generate subPreorder2 637