LC-0669 Medium LeetCode

669. Trim a Binary Search Tree

Tree Depth-First Search Binary Search Tree Binary Tree

Read the full problem statement on LeetCode.

Difficulty: medium Acceptance: 66% Topics: Tree, Depth-First Search, Binary Search Tree, Binary Tree

Reading material

Reference solution (spoiler · python)

# Time:  O(n)
# Space: O(h)

class Solution(object):
    def trimBST(self, root, L, R):
        """
        :type root: TreeNode
        :type L: int
        :type R: int
        :rtype: TreeNode
        """
        if not root:
            return None
        if root.val < L:
            return self.trimBST(root.right, L, R)
        if root.val > R:
            return self.trimBST(root.left, L, R)
        root.left, root.right = self.trimBST(root.left, L, R), self.trimBST(root.right, L, R)
        return root

Solution from kamyu104/LeetCode-Solutions · MIT