diff --git a/subtree-of-another-tree/Lustellz.ts b/subtree-of-another-tree/Lustellz.ts
new file mode 100644
index 000000000..0e5d8f169
--- /dev/null
+++ b/subtree-of-another-tree/Lustellz.ts
@@ -0,0 +1,29 @@
+// Runtime: 8ms
+// Memory: 63.23MB
+
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+
+const isSameTree = (p, q): boolean => {
+    if (!(p && q)) return p === q
+    if (p.val !== q.val) return false
+    return isSameTree(p.left, q.left) && isSameTree(p.right, q.right)
+}
+
+function isSubtree(root: TreeNode | null, subRoot: TreeNode | null): boolean {
+        if (!subRoot) return true
+    if (!root) return false
+    if (isSameTree(root, subRoot)) return true
+    return isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot)
+};