diff --git a/src/SearchInaBinarySearchTree700.java b/src/SearchInaBinarySearchTree700.java
deleted file mode 100644
index 21777d9..0000000
--- a/src/SearchInaBinarySearchTree700.java
+++ /dev/null
@@ -1,18 +0,0 @@
-public class SearchInaBinarySearchTree700 {
-    public TreeNode searchBST(TreeNode root, int val) {
-        if (root == null) {
-            return null;
-        }
-        if (root.val == val) {
-            return root;
-        }
-        if (root.val > val) {
-            return this.searchBST(root.left, val);
-        }
-        return this.searchBST(root.right, val);
-    }
-
-    public static void main(String[] args) {
-        System.out.println(new SearchInaBinarySearchTree700().searchBST(null, 1)); // null
-    }
-}
diff --git a/src/main/java/com/leetcode/easy/SearchInABinarySearchTree700.java b/src/main/java/com/leetcode/easy/SearchInABinarySearchTree700.java
new file mode 100644
index 0000000..50391ce
--- /dev/null
+++ b/src/main/java/com/leetcode/easy/SearchInABinarySearchTree700.java
@@ -0,0 +1,24 @@
+// Tags: Tree, DFS
+package com.leetcode.easy;
+
+import com.leetcode.datastructure.TreeNode;
+
+public class SearchInABinarySearchTree700 {
+    /**
+     * Time complexity: O(H), where H is a tree height.
+     * That results in O(logN) in the average case, and O(N) in the worst case.
+     * <p>
+     * Space complexity: O(H) to keep the recursion stack,
+     * i.e. O(logN) in the average case, and O(N) in the worst case.
+     */
+    public TreeNode searchBST(TreeNode root, int val) {
+        if (root == null || root.val == val) {
+            return root;
+        }
+        if (root.val > val) {
+            return this.searchBST(root.left, val);
+        } else {
+            return this.searchBST(root.right, val);
+        }
+    }
+}
diff --git a/src/test/java/com/leetcode/easy/SearchInABinarySearchTree700Test.java b/src/test/java/com/leetcode/easy/SearchInABinarySearchTree700Test.java
new file mode 100644
index 0000000..cd53db6
--- /dev/null
+++ b/src/test/java/com/leetcode/easy/SearchInABinarySearchTree700Test.java
@@ -0,0 +1,45 @@
+package com.leetcode.easy;
+
+import com.leetcode.datastructure.TreeNode;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+public class SearchInABinarySearchTree700Test {
+    private SearchInABinarySearchTree700 solution;
+
+    @BeforeEach
+    void setUp() {
+        solution = new SearchInABinarySearchTree700();
+    }
+
+    @Test
+    void testSearchBST_Example1() {
+        TreeNode root = new TreeNode(4);
+        root.left = new TreeNode(2);
+        root.right = new TreeNode(7);
+        root.left.left = new TreeNode(1);
+        root.left.right = new TreeNode(3);
+        int val = 2;
+
+        TreeNode result = solution.searchBST(root, val);
+
+        assertEquals(result, root.left);
+    }
+
+    @Test
+    void testSearchBST_Example2() {
+        TreeNode root = new TreeNode(4);
+        root.left = new TreeNode(2);
+        root.right = new TreeNode(7);
+        root.left.left = new TreeNode(1);
+        root.left.right = new TreeNode(3);
+        int val = 5;
+
+        TreeNode result = solution.searchBST(root, val);
+
+        assertNull(result);
+    }
+}