235. Lowest Common Ancestor of a Binary Search Tree
Runtime: 20 ms, faster than 22.41% of Java online submissions for Lowest Common Ancestor of a Binary Search Tree. Memory Usage: 50.1 MB, less than 25.70% of Java online submissions for Lowest Common Ancestor of a Binary Search Tree.
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
TreeNode head = root;
while(true) {
if(head == null)
break;
if(head.val <= q.val && head.val >= p.val
|| head.val >= q.val && head.val <= p.val) {
return head;
}
if(p.val >= head.val) {
head = head.right;
continue;
}
if(q.val < head.val) {
head = head.left;
continue;
}
}
return null;
}
}