Last updated on October 5th, 2024 at 05:31 pm

Here, We see Trim a Binary Search Tree LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Trim a Binary Search Tree LeetCode Solution

Problem Statement

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.

Example 1:

Input: root = [1,0,2], low = 1, high = 2
Output: [1,null,2]

Example 2:

Input: root = [3,0,4,null,2,null,null,1], low = 1, high = 3
Output: [3,2,null,1]

1. Trim a Binary Search Tree LeetCode Solution C++

class Solution {
public:
    TreeNode* trimBST(TreeNode* root, int low, int high) {
        if (!root) { 
            return root;
        }
        if (root->val >= low && root->val <= high) {
            root->left = trimBST(root->left, low, high);
            root->right = trimBST(root->right, low, high);
            return root;
        }
        if (root->val < low) {
            return trimBST(root->right, low, high);
        }
        return trimBST(root->left, low, high);
    }
};

2. Trim a Binary Search Tree Solution Java

class Solution {
    public TreeNode trimBST(TreeNode root, int low, int high) {
        if (root == null) {
            return null;
        }
        if (root.val >= low && root.val <= high) {
            root.left = trimBST(root.left, low, high);
            root.right = trimBST(root.right, low, high);
        } else if (root.val < low) {
            root = trimBST(root.right, low, high);
        } else if (root.val > high) {
            root = trimBST(root.left, low, high);
        }
        return root;
    }
}

3. Trim a Binary Search Tree Solution JavaScript

var trimBST = function(root, low, high) {
    if (root === null) {
        return null;
    }
    if (root.val > high) {
        return trimBST(root.left, low,high);
    }
    if (root.val < low) {
        return trimBST(root.right, low, high);
    }
    root.left = trimBST(root.left, low, high);
    root.right = trimBST(root.right, low, high);
    return root;     
};

4. Trim a Binary Search Tree Solution Python

class Solution(object):
    def trimBST(self, root, low, high):
		if not root: return root
		if root.val < low: return self.trimBST(root.right, low, high)
		if root.val > high: return self.trimBST(root.left, low, high)
		root.left = self.trimBST(root.left, low, high)
		root.right = self.trimBST(root.right, low, high)
		return root