一直二叉樹的前序周遊和中序周遊的結果，重建該二叉樹 Java代碼實作

package AlgorithmTest;

/**
 * Created by dell on 2015/10/5.
 */
public class RecreateBinaryTreeTest {
    public static void main(String[] args) {
        int[] preTraverseArr = new int[]{1, 2, 4, 7, 3, 5, 6, 8};
        int[] midTreverseArr = new int[]{4, 7, 2, 1, 5, 3, 8, 6};
        BinaryTree tree = BinaryTree.RecreateBinaryTree(preTraverseArr, midTreverseArr);
        System.out.println("preOrder:");
        tree.preOrderPrint();
        System.out.println("midOrder:");
        tree.midOrderPrint();
    }
}

class BinaryTree {
    private static class Node {
        private int value;
        private Node left;
        private Node right;
        public Node(int value){
            this.value = value;
            left = null;
            right = null;
        }
    }

    private Node root;

    public Node getRoot() {
        return root;
    }

    public void setRoot(Node root) {
        this.root = root;
    }

    public void preOrderPrint() {
        preOrderPrint(root);
    }

    public void midOrderPrint() {
        midOrderPrint(root);
    }
    private void preOrderPrint(Node root) {
        if (root != null) {
            System.out.println(root.value);
            preOrderPrint(root.left);
            preOrderPrint(root.right);
        }
    }

    private void midOrderPrint(Node root) {
        if (root != null) {
            midOrderPrint(root.left);
            System.out.println(root.value);
            midOrderPrint(root.right);
        }
    }


    public static BinaryTree RecreateBinaryTree(int[] preTraverseArr, int[] midTreverseArr) {
        Node root = RecreateBinaryTree(preTraverseArr, 0, midTreverseArr, 0, preTraverseArr.length);
        BinaryTree tree = new BinaryTree();
        tree.setRoot(root);
        return tree;
    }

    private static Node RecreateBinaryTree(int[] preTraverseArr, int be1,int[] midTreverseArr, int be2, int length) {
               if (0 != length){
                   Node root = new Node(preTraverseArr[be1]);

                   int index = findNum(midTreverseArr, be2, length, preTraverseArr[be1]);
                   int leftLength = index - be2;
                   int rightLenght = be2 + length - 1 - index;
                   Node nodeleft = RecreateBinaryTree(preTraverseArr, be1 + 1, midTreverseArr, be2, leftLength);
                   Node noderight = RecreateBinaryTree(preTraverseArr, be1 + leftLength + 1, midTreverseArr, index + 1, rightLenght);

                   root.left = nodeleft;
                   root.right= noderight;

                   return root;
               }
        return null;
    }

    private static int findNum(int[] array, int be, int length, final int findNum){
        for (int i = be; i < be + length; ++i){
            if (findNum == array[i]){
                return i;
            }
        }

        return -1;
    }
}