Added MyHashtable

Author: FreeTymeKiyan

Other/MyHashtable.java

@@ -0,0 +1,83 @@
+import java.util.*;
+
+/**
+ * Implement a hash table
+ *
+ * Tags: DS
+ */
+public class MyHashtable {
+    
+    LinkedList<Node>[] array;
+    int size;
+
+    class Node {
+        String key;
+        Object value;
+
+        public Node(String k, Object v) {
+            key = k;
+            value = v;
+        }
+    }
+
+    public MyHashtable(int size) {
+        array = new LinkedList[size];
+        this.size = size;
+    }
+    
+    public static void main(String[] args) {
+        
+    }
+
+    /**
+     * Create a new linkedlist if not in array, add value and set the list
+     * If linkedlist in array, search for the key and update value
+     * If key not found, add a new node with value to the end of list
+     */
+    public void put(String key, Object value) {
+        if (key == null || value == null) throw new IllegalArgumentException();
+        int index = hashcode(key) % size;
+        if (array[index] == null) {
+            LinkedList<Node> list = new LinkedList<Node>();
+            list.add(new Node(key, value));
+            array[index] = list;
+        } else {
+            LinkedList<Node> list = array[index];
+            boolean found = false;
+            for (Node n : list) {
+                if (n.key.equals(key)) {
+                    n.value = value;
+                    found = true;
+                    break;
+                }
+            }
+            if (!found) list.add(new Node(key, value));
+        }
+    }
+
+    /**
+     * If not in array, return null
+     * If in array, get the linkedlist and search for the key
+     * If no key, return null
+     */
+    public Object get(String key) {
+        if (key == null) return null; // validation
+        int index = hashcode(key) % size;
+        if (array[index] == null) return null;
+        LinkedList<Node> list = array[index];
+        for (Node n : list) {
+            if (key.equals(n.key)) {
+                return n.value;
+            }
+        }
+        return null;
+    }
+    
+    /**
+     * hash function to get the index
+     */
+    private int hashcode(String key) {
+        // TODO implement hash function
+        return 0;
+    }
+}