# Lowest Common Ancestor of a Binary Tree LeetCode Solution

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

## 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

## Lowest Common Ancestor of a Binary Tree LeetCode SolutionC++

``````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;
}
};```Code language: PHP (php)```

## Lowest Common Ancestor of a Binary Tree LeetCode SolutionJava

``````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;
}
}```Code language: PHP (php)```

## Lowest Common Ancestor of a Binary Tree SolutionJavaScript

``````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);
};```Code language: JavaScript (javascript)```

## Lowest Common Ancestor of a Binary Tree SolutionPython

``````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)``````
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