lru here we come

src/__tests__/LRU.ts

@@ -0,0 +1,8 @@
+import ArrayList from "@code/LRU";
+
+test("LRU", function () {
+    const lru = new LRU<number>(10);
+
+    lru.
+});
+

src/global.d.ts

@@ -31,3 +31,8 @@ declare type GeneralNode<T> = {
     value: T;
     children: GeneralNode<T>[];
 };
+
+declare interface ILRU<K, V> {
+    update(key: K, value: V): void;
+    get(key: K): V | undefined;
+}