Binary Search Tree

Table of Contents

• 270. Closest Binary Search Tree Value (Easy) 👑
• 272. Closest Binary Search Tree Value II (Hard) 👑
• 255. Verify Preorder Sequence in Binary Search Tree (Medium) 👑
• 1214. Two Sum BSTs (Medium) 👑
• 333. Largest BST Subtree (Medium) 👑

270. Closest Binary Search Tree Value

• LeetCode | 力扣

• Tags: Binary Search, Tree, Depth First Search, Binary Search Tree, Binary Tree

272. Closest Binary Search Tree Value II

• LeetCode | 力扣

• Tags: Two Pointers, Stack, Tree, Depth First Search, Binary Search Tree, Heap Priority Queue, Binary Tree

255. Verify Preorder Sequence in Binary Search Tree

• LeetCode | 力扣

• Tags: Array, Stack, Tree, Binary Search Tree, Recursion, Monotonic Stack, Binary Tree

Python

from typing import List


# BST
def verifyPreorder(preorder: List[int]) -> bool:
    stack = []
    low = float("-inf")

    for value in preorder:
        if value < low:
            return False
        while stack and value > stack[-1]:
            low = stack.pop()
        stack.append(value)

    return True


if __name__ == "__main__":
    assert verifyPreorder([8, 5, 1, 7, 10, 12]) is True
    assert verifyPreorder([8, 5, 4, 3, 2, 1]) is True

1214. Two Sum BSTs

• LeetCode | 力扣

• Tags: Two Pointers, Binary Search, Stack, Tree, Depth First Search, Binary Search Tree, Binary Tree

333. Largest BST Subtree

• LeetCode | 力扣

• Tags: Dynamic Programming, Tree, Depth First Search, Binary Search Tree, Binary Tree

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