# Lowest Common Ancestor of a Binary Search Tree LeetCode Solution

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

## 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

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

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

## Lowest Common Ancestor of a Binary Search Tree LeetCode SolutionJava

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

## Lowest Common Ancestor of a Binary Search Tree SolutionJavaScript

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

## Lowest Common Ancestor of a Binary Search Tree SolutionPython

``````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```Code language: CSS (css)```
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