Adds LRU cache

src/main/java/net/abhinavsarkar/algorist/LRUCache.java

@@ -0,0 +1,74 @@
+package net.abhinavsarkar.algorist;
+
+import java.util.Iterator;
+import java.util.Optional;
+
+public class LRUCache<K,V>
+{
+
+    private final LRWCache<K,V> store;
+
+    public LRUCache(int capacity) {
+        this.store = new LRWCache<>(capacity);
+    }
+
+    public Optional<V> get(K key)
+    {
+        Optional<V> val = store.get(key);
+        val.ifPresent(v -> put(key, v));
+        return val;
+    }
+
+    public void remove(K key)
+    {
+        store.remove(key);
+    }
+
+    public void put(K key, V val)
+    {
+        store.put(key, val);
+    }
+
+    public int size()
+    {
+        return store.size();
+    }
+
+    public Iterator<K> iterator()
+    {
+        return store.iterator();
+    }
+
+    @Override
+    public String toString()
+    {
+        return store.toString();
+    }
+
+    public static void main(String[] args)
+    {
+        LRUCache<String, String> cache = new LRUCache<>(4);
+        cache.put("a", "abhinav");
+        cache.put("b", "batman");
+        cache.put("c", "carol");
+        cache.put("z", "zellman");
+        System.out.println(cache);
+
+        cache.put("w", "walker");
+        System.out.println(cache);
+
+        cache.put("c", "carly");
+        System.out.println(cache);
+
+        cache.put("x", "xander");
+        System.out.println(cache);
+
+        cache.get("w");
+        System.out.println(cache);
+
+        cache.put("a", "abhinav");
+        System.out.println(cache);
+    }
+
+
+}