Last updated on October 5th, 2024 at 08:49 pm

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

*List of all LeetCode Solution*

*List of all LeetCode Solution*

## Topics

Tree

## Companies

Amazon, Facebook, Microsoft, Twitter

## Level of Question

Medium

**Lowest Common Ancestor of a Binary Search Tree LeetCode Solution**

## Table of Contents

**Problem Statement**

Given a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST.

According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes `p`

and `q`

as the lowest node in `T`

that has both `p`

and `q`

as descendants (where we allow **a node to be a descendant of itself**).”

**Example 1:**

**Input:** root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 8 **Output:** 6 **Explanation:** The LCA of nodes 2 and 8 is 6.

**Example 2:**

**Input:** root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 4 **Output:** 2 **Explanation:** The LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.

**Example 3:****Input:** root = [2,1], p = 2, q = 1 **Output:** 2

**1. Lowest Common Ancestor of a Binary Search Tree LeetCode Solution C++**

class Solution { public: TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) { if(root==NULL) return nullptr; if(root->val>p->val&&root->val>q->val) return lowestCommonAncestor(root->left,p,q); if(root->val<p->val&&root->val<q->val) return lowestCommonAncestor(root->right,p,q); return root; } };

**2. Lowest Common Ancestor of a Binary Search Tree LeetCode Solution Java**

class Solution { public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) { if(root==null) return null; if(p.val<root.val&&q.val<root.val) { return lowestCommonAncestor(root.left,p,q); } else if(p.val>root.val&&q.val>root.val){ return lowestCommonAncestor(root.right,p,q); } else return root; } }

**3. Lowest Common Ancestor of a Binary Search Tree Solution JavaScript**

var lowestCommonAncestor = function(root, p, q) { while (root) { if (root.val < p.val && root.val < q.val) { root = root.right; } else if (root.val > p.val && root.val > q.val) { root = root.left; } else { break; } } return root; };

**4. Lowest Common Ancestor of a Binary Search Tree Solution Python**

class Solution(object): def lowestCommonAncestor(self, root, p, q): if root: if root.val > p.val and root.val > q.val: return self.lowestCommonAncestor(root.left, p, q) elif root.val < p.val and root.val < q.val: return self.lowestCommonAncestor(root.right, p, q) else: return root