lru cache

Author: dheeraj9198

src/LRUCache.java

@@ -0,0 +1,87 @@
+import java.util.HashMap;
+
+/**
+ * Created by dheeraj on 7/8/2016.
+ */
+public class LRUCache {
+
+    private static DLLNode startDllNode, endDllNode;
+
+    private static int maxSize = 3;
+    private static int size = 0;
+
+    private static class DLLNode {
+        int data, value;
+        DLLNode prev, next;
+
+        public DLLNode(int data, int value) {
+            this.data = data;
+            this.value = value;
+        }
+    }
+
+    private static HashMap<Integer, DLLNode> integerDLLNodeHashMap = new HashMap<Integer, DLLNode>();
+
+    private static void addData(int key, int value) {
+        DLLNode dllNode = new DLLNode(key, value);
+        integerDLLNodeHashMap.put(key, dllNode);
+        if (size == 0) {
+            startDllNode = dllNode;
+            endDllNode = dllNode;
+            size++;
+        } else if (size < maxSize) {
+            dllNode.next = startDllNode;
+            startDllNode.prev = dllNode;
+            startDllNode = dllNode;
+            size++;
+        } else {
+            dllNode.next = startDllNode;
+            startDllNode.prev = dllNode;
+            startDllNode = dllNode;
+
+            DLLNode end = endDllNode;
+            end.next = null;
+            DLLNode prevEnd = end.prev;
+            end.prev = null;
+            prevEnd.next = null;
+            endDllNode = prevEnd;
+            integerDLLNodeHashMap.remove(end.data);
+        }
+    }
+
+    private static int getData(int key) {
+        DLLNode dllNode = integerDLLNodeHashMap.get(key);
+        if (dllNode == null) {
+            return -1;
+        } else {
+            if (dllNode == endDllNode) {
+                endDllNode = endDllNode.prev;
+            }
+            if (dllNode.prev != null) {
+                dllNode.prev.next = dllNode.next;
+            }
+            if (dllNode.next != null) {
+                dllNode.next.prev = dllNode.prev;
+            }
+            dllNode.prev = null;
+            dllNode.next = startDllNode;
+            startDllNode.prev = dllNode;
+            startDllNode = dllNode;
+            return dllNode.data;
+        }
+    }
+
+
+    public static void main(String[] strings) {
+        addData(1, 1);
+        addData(2, 2);
+        addData(3, 3);
+
+        getData(2);
+
+        addData(4, 4);
+        System.out.println();
+    }
+
+
+}

src/Heap.java src/heap/Heap.javasrc/Heap.java renamed to src/heap/Heap.java

@@ -1,3 +1,5 @@
+package heap;
+
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
 import java.util.PriorityQueue;

src/Array/KthMinElemUsingMaxHeap.java src/heap/KthMinElemUsingMaxHeap.javasrc/Array/KthMinElemUsingMaxHeap.java renamed to src/heap/KthMinElemUsingMaxHeap.java

@@ -1,4 +1,4 @@
-package Array;
+package heap;
 
 /**
  * Created by dheeraj on 7/5/2016.

src/MyHeap.java src/heap/MyHeap.javasrc/MyHeap.java renamed to src/heap/MyHeap.java

@@ -1,3 +1,5 @@
+package heap;
+
 /**
  * Created by dheeraj on 11/1/15.
  */