Adds loadFactor in OAHT

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

@@ -0,0 +1,5 @@
+package net.abhinavsarkar.algorist;
+
+public class BinarySearchTree
+{
+}

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

@@ -9,19 +9,35 @@ public class OpenAddressingHashTable<K, V> implements Iterable<OpenAddressingHas
 
     private static final Entry REMOVED = new Entry(0,0);
     private Object[] store;
+    private final double loadFactor;
     private final ProbingStrategy probingStrategy;
     private Entry<K, V> head;
     private Entry<K, V> tail;
     private int size;
+    private int actualSize;
 
-    public OpenAddressingHashTable(int initialCapacity, ProbingStrategy probingStrategy) {
+    public OpenAddressingHashTable(int initialCapacity, double loadFactor, ProbingStrategy probingStrategy) {
-        this.store = new Object[initialCapacity];
+        this.store = new Object[nextPowerOf2(initialCapacity)];
+        this.loadFactor = loadFactor;
         this.probingStrategy = probingStrategy;
     }
 
-    public OpenAddressingHashTable(int initialCapacity)
+    public OpenAddressingHashTable(int initialCapacity, double loadFactor)
     {
-        this(initialCapacity, new LinearProbing());
+        this(initialCapacity, loadFactor, new LinearProbing());
+    }
+
+    public OpenAddressingHashTable(int initialCapacity) {
+        this(initialCapacity, 0.75);
+    }
+
+    public OpenAddressingHashTable() {
+        this(16);
+    }
+
+    private static int nextPowerOf2(int num)
+    {
+        return num == 1 ? 1 : Integer.highestOneBit(num - 1) * 2;
     }
 
     public Optional<V> get(K key) {
@@ -53,25 +69,23 @@ public class OpenAddressingHashTable<K, V> implements Iterable<OpenAddressingHas
     }
 
     public void put(K key, V val) {
-        if (!doPut(new Entry<>(key, val), store, false)) {
+        if (actualSize >= loadFactor * store.length) {
             resize();
-            put(key, val);
         }
+        doPut(new Entry<>(key, val), store, false);
     }
 
     private void resize() {
         Object[] nStore = new Object[store.length * 2];
         for (Entry<K, V> entry : this)
         {
-            if (!doPut(entry, nStore, true))
+            doPut(entry, nStore, true);
-            {
-                throw new IllegalStateException("Something is wrong");
-            }
         }
-        this.store = nStore;
+        store = nStore;
+        actualSize = size;
     }
 
-    private boolean doPut(Entry<K,V> nEntry, Object[] store, boolean resize) {
+    private void doPut(Entry<K,V> nEntry, Object[] store, boolean resize) {
         int trial = 0;
         int baseIndex = calcIndex(nEntry.key, store.length);
         while (trial < store.length) {
@@ -83,10 +97,13 @@ public class OpenAddressingHashTable<K, V> implements Iterable<OpenAddressingHas
                 {
                     linkNewEntry(nEntry);
                     size++;
+                    if (entry != REMOVED) {
+                        actualSize++;
+                    }
                 }
 
                 store[index] = nEntry;
-                return true;
+                return;
             }
             else if (entry.key.equals(nEntry.key))
             {
@@ -94,11 +111,11 @@ public class OpenAddressingHashTable<K, V> implements Iterable<OpenAddressingHas
                     linkUpdatedEntry(entry);
                 }
                 entry.val = nEntry.val;
-                return true;
+                return;
             }
             trial++;
         }
-        return false;
+        throw new IllegalStateException("Impossible");
     }
 
     private void linkNewEntry(Entry<K, V> nEntry)
@@ -278,11 +295,15 @@ public class OpenAddressingHashTable<K, V> implements Iterable<OpenAddressingHas
     public static void main(String[] args)
     {
         OpenAddressingHashTable<String, String> table =
-                new OpenAddressingHashTable<>(4, new LinearProbing());
+                new OpenAddressingHashTable<>(2, 0.75, new LinearProbing());
         table.put("a", "abhinav");
         table.put("b", "batman");
         table.put("c", "carol");
         table.put("c", "carly");
+
+        table.remove("a");
+        System.out.println(table.size());
+
         table.put("z", "zellman");
         table.put("w", "walker");
         System.out.println(table);