feat: lowest-common-ancestor-of-a-binary-search-tree

Author: minji-go

lowest-common-ancestor-of-a-binary-search-tree/minji-go.java

@@ -0,0 +1,24 @@
+/**
+ * <a href="https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/">week13-2. lowest-common-ancestor-of-a-binary-search-tree</a>
+ * <li>Description: find the lowest common ancestor (LCA) node of two given nodes in the BST. </li>
+ * <li>Topics: Tree, Depth-First Search, Binary Search Tree, Binary Tree </li>
+ * <li>Time Complexity: O(H), Runtime 5ms       </li>
+ * <li>Space Complexity: O(1), Memory 44.91MB   </li>
+ */
+
+class Solution {
+    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
+        TreeNode node = root;
+        while (node != null) {
+            if (p.val < node.val && q.val < node.val) {
+                node = node.left;
+            } else if (p.val > node.val && q.val > node.val) {
+                node = node.right;
+            } else {
+                return node;
+            }
+        }
+
+        throw new IllegalArgumentException();
+    }
+}