In this post we will solve the LeetCode 669 Trim a Binary Search Tree problem. This problem is ranked a Medium by LeetCode. It took me some extra time to figure out what I had to do.
Given the root of a binary search tree and the lowest and highest boundaries as low and high, trim the tree so that all its elements lies in [low, high]. Trimming the tree should not change the relative structure of the elements that will remain in the tree (i.e., any node's descendant should remain a descendant). It can be proven that there is a unique answer. Return the root of the trimmed binary search tree. Note that the root may change depending on the given bounds. Constraints: o The number of nodes in the tree in the range [1, 10^4]. o 0 <= Node.val <= 10^4 o The value of each node in the tree is unique. o root is guaranteed to be a valid binary search tree. o 0 <= low <= high <= 10^4 Related Topics: o Tree o Depth-First Search o Binary Search Tree o Binary Tree
The problem clearly states that we are presented with a binary search tree which specifies the relationship between node values. Continue reading “LeetCode 669. Trim a Binary Search Tree in Java”