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Kth Smallest Element In BST

Detailed guide and Python implementation for the 'Kth Smallest Element In BST' problem.

Problem Statement

Easy

Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree.

The tree is represented as a level-order list. Implement a function kthSmallest(root: list, k: int) -> int.

Constraints
  • The number of nodes in the tree is n
  • 1 <= k <= n <= 10000
  • 0 <= Node.val <= 10000

Examples

Example 1
Input
[3,1,4,None,2], 1
Output
1
Explanation

The in-order traversal is [1,2,3,4]. The 1st smallest is 1.

Example 2
Input
[5,3,6,2,4,None,None,1], 3
Output
3
Explanation

The in-order traversal is [1,2,3,4,5,6]. The 3rd smallest is 3.

Need a Hint?
Consider using Trees-specific data structures like sets or heaps.
Edge Cases to Watch
  • Empty input structures
  • Single element inputs
  • Large numerical bounds

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