leetcode---Construct Binary Tree from Inorder and Postorder Traversal

Given inorder and postorder traversal of a tree, construct the binary tree.

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    TreeNode* make(vector<int>& inorder, int inLow, int inHigh, vector<int>& postorder, int posLow, int posHigh)    {        if(posLow > posHigh)            return NULL;        else if(posLow == posHigh)            return new TreeNode(postorder[posHigh]);        TreeNode *root = new TreeNode(postorder[posHigh]);  //根        int i = inLow;  //根结点在中序遍历中的下标        for(; i<=inHigh; i++)        {            if(inorder[i] == postorder[posHigh])                break;        }        int leftLen = i - inLow;        root->left = make(inorder, inLow, inLow+leftLen, postorder, posLow, posLow+leftLen-1);        root->right = make(inorder, inLow+leftLen+1, inHigh, postorder, posLow+leftLen, posHigh-1);        return root;    }    TreeNode* buildTree(vector<int>& inorder, vector<int>& postorder)     {        return make(inorder, 0, inorder.size()-1, postorder, 0, postorder.size()-1);    }};