<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.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def createBinaryTree(self, descriptions: List[List[int]]) -> Optional[TreeNode]:

        hs = defaultdict(list)
        seen = set()
        main = set()

        for i, j, k in descriptions:
            hs[i].append((j, k))
            seen.add(i)
            main.add(j)

        # print(hs)

        for i in main:
            if i in seen:
                seen.remove(i)

        tmp = TreeNode(list(seen)[0])

        queue = deque([tmp])
        # print(seen)

        while queue:

            node = queue.popleft()

            for e, p in hs[node.val]:
                n = TreeNode(e)
                if p == 1:
                    node.left = n
                else:
                    node.right = n
                queue.append(n)
        
        # print(tmp)

        return tmp







       
        # adj = defaultdict(list)

        # for n in hs:
        #     tmp = TreeNode(n)
        #     adj[tmp] = []

        #     for e in hs[n]:
        #         if e in adj:
        #             adj[tmp].append(e)

        # for n in hs:
        #     tmp = TreeNode(n)
        #     for c, p in hs[n]:
        #         if p == 1:
        #             tmp.left = 




        # arr = set()

        # for n, k, l in descriptions:
        #     arr.add(n)
        #     arr.add(k)
        
        # tmp = sorted(arr)

        # print(tmp)
        
        # def back(l, r):

        #     if l >= r:
        #         return None

        #     mid = (l + r) // 2

        #     node = TreeNode(tmp[mid])

        #     node.left = back(l, mid)
        #     node.right = back(mid + 1, r)

        #     return node 

        # return back(0, len(tmp))

        
1720