<p>You are given a 2D integer array <code>descriptions</code> where <code>descriptions[i] = [parent<sub>i</sub>, child<sub>i</sub>, isLeft<sub>i</sub>]</code> indicates that <code>parent<sub>i</sub></code> is the <strong>parent</strong> of <code>child<sub>i</sub></code> in a <strong>binary</strong> tree of <strong>unique</strong> values. Furthermore,</p>

<ul>
	<li>If <code>isLeft<sub>i</sub> == 1</code>, then <code>child<sub>i</sub></code> is the left child of <code>parent<sub>i</sub></code>.</li>
	<li>If <code>isLeft<sub>i</sub> == 0</code>, then <code>child<sub>i</sub></code> is the right child of <code>parent<sub>i</sub></code>.</li>
</ul>

<p>Construct the binary tree described by <code>descriptions</code> and return <em>its <strong>root</strong></em>.</p>

<p>The test cases will be generated such that the binary tree is <strong>valid</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/02/09/example1drawio.png" style="width: 300px; height: 236px;" />
<pre>
<strong>Input:</strong> descriptions = [[20,15,1],[20,17,0],[50,20,1],[50,80,0],[80,19,1]]
<strong>Output:</strong> [50,20,80,15,17,19]
<strong>Explanation:</strong> The root node is the node with value 50 since it has no parent.
The resulting binary tree is shown in the diagram.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/02/09/example2drawio.png" style="width: 131px; height: 300px;" />
<pre>
<strong>Input:</strong> descriptions = [[1,2,1],[2,3,0],[3,4,1]]
<strong>Output:</strong> [1,2,null,null,3,4]
<strong>Explanation:</strong> The root node is the node with value 1 since it has no parent.
The resulting binary tree is shown in the diagram.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= descriptions.length &lt;= 10<sup>4</sup></code></li>
	<li><code>descriptions[i].length == 3</code></li>
	<li><code>1 &lt;= parent<sub>i</sub>, child<sub>i</sub> &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= isLeft<sub>i</sub> &lt;= 1</code></li>
	<li>The binary tree described by <code>descriptions</code> is valid.</li>
</ul>

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    TreeNode* createBinaryTree(vector<vector<int>>& descriptions) {
        map<int,TreeNode*>m;
        vector<int>children;
        TreeNode* root=NULL;
        for(int i=0;i<descriptions.size();i++){
            int parent=descriptions[i][0];
            int child=descriptions[i][1];
            int d=descriptions[i][2];

            if(m.find(parent)!=m.end()){


                if(d==1){

            if(m.find(child)==m.end()){
            TreeNode* l=new TreeNode(child);
            m[parent]->left=l;
            m[child]=l;
            children.push_back(child);
            
           
            }
            else{
                m[parent]->left=m[child];
                 children.push_back(child);
            
                
            }


           }
           else{



             if(m.find(child)==m.end()){
            TreeNode* r=new TreeNode(child);
            m[parent]->right=r;
            m[child]=r;
            children.push_back(child);
            
           
            }
            else{
                m[parent]->right=m[child];
                 children.push_back(child);
            
                
            }
           }

            }
else{
           TreeNode* temp=new TreeNode(parent);
          
           if(d==1){
            if(m.find(child)==m.end()){
            TreeNode* l=new TreeNode(child);
            temp->left=l;
            m[child]=l;
            children.push_back(child);
            
           
            }
            else{
                temp->left=m[child];
                 children.push_back(child);

            }
              m[parent]=temp;
           }
           else{


            if(m.find(child)==m.end()){
            TreeNode* r=new TreeNode(child);
            temp->right=r;
            m[child]=r;
            children.push_back(child);
            
           
            }
            else{
                temp->right=m[child];
                children.push_back(child);
                
            }
              m[parent]=temp;

           }
          
          
         
}

        }

   for(auto it:m){
     

       auto i = find(children.begin(), children.end(), it.first);

    // Check if element was found
    if (i == children.end()) {
        root=it.second;
        break;
   }   
   }  
   return root;
        
    }
};
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