Last updated on October 5th, 2024 at 06:07 pm

Here, We see ** Lowest Common Ancestor of a Binary 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, Apple, Facebook, LinkedIn, Microsoft

## Level of Question

Medium

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

## Table of Contents

**Problem Statement**

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

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 = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1 **Output:** 3 **Explanation:** The LCA of nodes 5 and 1 is 3.

**Example 2:**

**Input:** root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 4 **Output:** 5 **Explanation:** The LCA of nodes 5 and 4 is 5, since a node can be a descendant of itself according to the LCA definition.

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

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

class Solution { public: TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) { if (!root || root == p || root == q) return root; TreeNode* left = lowestCommonAncestor(root->left, p, q); TreeNode* right = lowestCommonAncestor(root->right, p, q); return !left ? right : !right ? left : root; } };

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

class Solution { public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) { if (root == null || root == p || root == q) return root; TreeNode left = lowestCommonAncestor(root.left, p, q); TreeNode right = lowestCommonAncestor(root.right, p, q); return left == null ? right : right == null ? left : root; } }

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

var lowestCommonAncestor = function(root, p, q) { if (!root || root === p || root === q) return root; var resL = lowestCommonAncestor(root.left, p, q); var resR = lowestCommonAncestor(root.right, p, q); return (resL && resR) ? root : (resL || resR); };

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

class Solution(object): def lowestCommonAncestor(self, root, p, q): if root in (None, p, q): return root subs = [self.lowestCommonAncestor(kid, p, q) for kid in (root.left, root.right)] return root if all(subs) else max(subs)