重建二叉树

输入某二叉树的前序遍历和中序遍历的结果，请重建出该二叉树。假设输入的前序遍历和中序遍历的结果中都不含重复的数字。例如输入前序遍历序列{1,2,4,7,3,5,6,8}和中序遍历序列{4,7,2,1,5,3,8,6}，则重建二叉树并返回。

 

public class Solution {
    public TreeNode reConstructBinaryTree(int[] pre,int[] in) {
        TreeNode root = reConstructBinaryTree(pre,0,pre.length-1,in,0,in.length-1);
        return root;
    }
    public TreeNode reConstructBinaryTree(int[] PreOrderTraverse,int PreOrderStart,int PreOrderEnd, int[] InorderTraverse,int InOrderStart,int InoderEnd){
 
        if(PreOrderStart > PreOrderEnd || InOrderStart > InoderEnd){
            return null;
        }
 
        TreeNode root = new TreeNode(PreOrderTraverse[PreOrderStart]);
 
        for(int i = InOrderStart ; i<= InoderEnd ;i++){
            if(InorderTraverse[i] == PreOrderTraverse[PreOrderStart]){
                root.left = reConstructBinaryTree(PreOrderTraverse,PreOrderStart+1,PreOrderStart + i - InOrderStart,InorderTraverse,InOrderStart,i-1);
                root.right = reConstructBinaryTree(PreOrderTraverse,PreOrderStart+i-InOrderStart+1,PreOrderEnd,InorderTraverse,i+1,InoderEnd);
            }
        }
 
        return root;
    }
}