Construct Binary Tree from Inorder and Postorder Traversal

Description:

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

Note:
You may assume that duplicates do not exist in the tree.

Code:

TreeNode * buildTree(vector<int>& inorder, int inBegin, int inEnd, vector<int>& postorder, int postBegin, int postEnd)
 {
    TreeNode*root =NULL;

    if (postEnd >= postBegin)
    {
        root = new TreeNode(postorder[postEnd]);
    
        int rootIndex = 0;
        for (int i = inBegin; i <= inEnd; ++i)
        {
            if (inorder[i] == postorder[postEnd])
            {
                rootIndex = i;
                break;
            }
        }
        
        if (rootIndex!=inBegin)
        {
            root->left = buildTree( inorder, inBegin, rootIndex-1, postorder, postBegin, postBegin+(rootIndex-inBegin)-1);
        }
        if (rootIndex!=inEnd)
        {
            root->right = buildTree(inorder, rootIndex+1, inEnd, postorder, postBegin+(rootIndex-inBegin), postEnd-1);
        }
    }
    return root;  
 }
    TreeNode* buildTree(vector<int>& inorder, vector<int>& postorder) {
      return buildTree(inorder, 0, inorder.size()-1, postorder, 0, postorder.size()-1);  
    }