<p>Given two integer arrays <code>inorder</code> and <code>postorder</code> where <code>inorder</code> is the inorder traversal of a binary tree and <code>postorder</code> is the postorder traversal of the same tree, construct and return <em>the binary tree</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/tree.jpg" style="width: 277px; height: 302px;" />
<pre>
<strong>Input:</strong> inorder = [9,3,15,20,7], postorder = [9,15,7,20,3]
<strong>Output:</strong> [3,9,20,null,null,15,7]
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> inorder = [-1], postorder = [-1]
<strong>Output:</strong> [-1]
</pre>

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

<ul>
	<li><code>1 &lt;= inorder.length &lt;= 3000</code></li>
	<li><code>postorder.length == inorder.length</code></li>
	<li><code>-3000 &lt;= inorder[i], postorder[i] &lt;= 3000</code></li>
	<li><code>inorder</code> and <code>postorder</code> consist of <strong>unique</strong> values.</li>
	<li>Each value of <code>postorder</code> also appears in <code>inorder</code>.</li>
	<li><code>inorder</code> is <strong>guaranteed</strong> to be the inorder traversal of the tree.</li>
	<li><code>postorder</code> is <strong>guaranteed</strong> to be the postorder traversal of the tree.</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 buildTree(self, inorder: List[int], postorder: List[int]) -> Optional[TreeNode]:
        if not inorder:
            return None


        self.deep = 0
        
        def aux(node, is_idx, ie_idx, ps_idx, pe_idx):
            idx = inorder.index(node.val)
            print(f"node:{node}, is_idx:{is_idx}, ie_idx:{ie_idx}, ps_idx:{ps_idx}, pe_idx:{pe_idx}")
            # self.deep+=1
            # if self.deep > 5 or pe_idx <=0:
            #     return
            
            if is_idx <= idx-1 and ps_idx<=ps_idx+(idx-is_idx)-1:
                node.left = TreeNode(val = postorder[ps_idx + (idx- is_idx)-1])
                aux(node.left, is_idx, idx-1, ps_idx , ps_idx + (idx - is_idx)-1)
            if idx+1 <= ie_idx and ps_idx+(idx-is_idx)<=pe_idx-1:
                node.right = TreeNode(val = postorder[pe_idx-1])
                aux(node.right, idx+1, ie_idx, ps_idx + (idx- is_idx), pe_idx-1)
            

        head = TreeNode(val = postorder[-1])
        
        aux(head, 0, len(inorder)-1, 0, len(inorder)-1)
        print(head)
        return head
    
    

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