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Intuition

This is a straight-forward tree problem. We are provided with two clone trees, and are required to return a corresponding node of type TreeNode in cloned.

So, we traverse both the trees at the same pace and then once we find the target node in original, we return the cloned node at that instant.

Code

Python3

def getTargetCopy(self, original: TreeNode, cloned: TreeNode, target: TreeNode) -> TreeNode:
    if not original or not cloned: return None
 
    if original == target: return cloned
 
    return self.getTargetCopy(original.left, cloned.left, target) or self.getTargetCopy(original.right, cloned.right, target)

Big O Analysis

• Runtime

  The runtime complexity here is $O(N)$ since we would be visiting all nodes in the tree.

• Memory

  The memory usage is $O(1)$ since we are not using any extra data structure.

— A

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