Closest Binary Search Tree Value
To find the value in a binary search tree (BST) that is closest to a given target, you can perform an inorder traversal while keeping track of the closest value found so far. Since the tree is a BST, the inorder traversal will process the nodes in ascending order, allowing you to compare each value to the target.
Here’s a stepbystep approach:
 Initialize Variables: Initialize variables to track the closest value and the minimum difference found so far.
 InOrder Traversal: Perform an inorder traversal of the tree.
 Compare Values: During the traversal, compare each node’s value to the target and update the closest value if a smaller difference is found.
 Handle Ties: If there are multiple answers with the same difference, return the smallest value.


Key Takeaways
 The problem can be solved by performing an inorder traversal and comparing each value to the target.
 The time complexity of this solution is (O(N)), where (N) is the number of nodes in the tree. The space complexity is also (O(N)) in the worst case, as it may need to store the entire tree in the call stack. In a balanced BST, the space complexity would be (O(\log N)).
LC official solution works. Here is the code for solving the problem:


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