LeetCode - Tree - Trim Binary Tree

Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You might need to change the root of the tree, so the result should return the new root of the trimmed binary search tree.

Example 1:

Input: 
    1
   / \
  0   2

  L = 1
  R = 2

Output: 
    1
      \
       2

 

Example 2:

Input: 
    3
   / \
  0   4
   \
    2
   /
  1

  L = 1
  R = 3

Output: 
      3
     / 
   2   
  /
 1

 

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public TreeNode trimBST(TreeNode root, int L, int R) {
       if(root == null) return null;
       if(root.val<L || root.val>R ){
           if(root.val<L && root.val<R){
               root = trimBST(root.right,L,R);
           }
           else if(root.val>L && root.val>R){
               root = trimBST(root.left,L,R);
           }else{
               root = null;
           }
       }else{
           root.left = trimBST(root.left,L,R);
           root.right = trimBST(root.right,L,R);
       }
       
        return root;
    }
}

Recent Updates

Recent updates on DevOpsPal

Social

Follow us of social for latest updates.

DevOps Hub

Links to get started.