Construct Binary Tree from Preorder and Inorder Traversal @LeetCode

PROBLEM :

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

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

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SIMPLE c++ IMPLEMENTATION : (Recursive Solution)
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/**
 * 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* buildTree(vector<int>& preorder, vector<int>& inorder) {
        TreeNode* root ;
        int size=inorder.size() ;
        if(size==0)
            return NULL ;
       
        size=0 ;
        root=BuiltPostOrderTree(inorder,preorder,0,inorder.size()-1,&size) ;
        return root ;
    }
   
    TreeNode* BuiltPostOrderTree(vector<int> &inorder,vector<int> &preorder,int begin,int end,int *curr){
        if(begin>end)
            return NULL ;
       
        TreeNode* root=new TreeNode(preorder[(*curr)++]);
       
        if(begin==end)
            return root ;
       
        int index=FindIndex(inorder,root->val) ;
       
        root->left=BuiltPostOrderTree(inorder,preorder,begin,index-1,&(*curr)) ;
        root->right=BuiltPostOrderTree(inorder,preorder,index+1,end,&(*curr)) ;
       
        return root ;
    }
   
    int FindIndex(vector<int> &inorder,int data){
    for(int i=0;i<inorder.size();i++){
    if(inorder[i]==data)
    return i ;
}
}
};

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