Create a Program to Implement Hash and Maps in Java Assignment Solution.

Source Code

import java.util.HashSet; import java.util.Set; public class MyHashMap { // Holds an array of linked list of hash nodes private Object[] nodes = new Object[8]; // Remove all elements public void clear() { for (int i = 0; i < nodes.length; i++) { nodes[i] = null; } } // Check if key exists public boolean containsKey(K key) { int index = hash(key); if (nodes[index] == null) { return false; } HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { if (currentNode.getKey().equals(key)) { return true; } currentNode = currentNode.getNext(); } return false; } // Check if value exists public boolean containsValue(V value) { for (Object object : nodes) { if (object != null) { HashNode currentNode = (HashNode) object; while (currentNode != null) { if (currentNode.getValue().equals(value)) { return true; } currentNode = currentNode.getNext(); } } } return false; } // Get the value associated with the key public V get(K key) { int index = hash(key); if (nodes[index] == null) { return null; } HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { if (currentNode.getKey().equals(key)) { return currentNode.getValue(); } currentNode = currentNode.getNext(); } return null; } // Check if empty public boolean isEmpty() { for (Object object : nodes) { if (object != null) { return false; } } return true; } // Return the set of keys public Set keySet() { Set set = new HashSet<>(); for (Object object : nodes) { if (object != null) { HashNode currentNode = (HashNode) object; while (currentNode != null) { set.add(currentNode.getKey()); currentNode = currentNode.getNext(); } } } return set; } // Add or update a new pair public void put(K key, V value) { int index = hash(key); // No collisions for fresh slot if (nodes[index] == null) { nodes[index] = new HashNode<>(key, value); return; } // Search if the key already exists HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { if (currentNode.getKey().equals(key)) { // Do update ofkey already exists currentNode.setValue(value); return; } currentNode = currentNode.getNext(); } // Do add in front HashNode node = new HashNode<>(key, value); node.setNext((HashNode) nodes[index]); nodes[index] = node; } // Remove the key and returnthe associated value public V remove(K key) { int index = hash(key); if (nodes[index] == null) { return null; } HashNode previousNode = null; HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { if (currentNode.getKey().equals(key)) { if (currentNode == nodes[index]) { // Case deleting the head nodes[index] = ((HashNode) nodes[index]).getNext(); } else { // Case deleting in-between previousNode.setNext(currentNode.getNext()); } return currentNode.getValue(); } previousNode = currentNode; currentNode = currentNode.getNext(); } return null; } // Return the numberof elements public int size() { int overallSize = 0; for (int i = 0; i < nodes.length; i++) { overallSize += listSize(i); } return overallSize; } // Print out the table public void printTable() { int conflicts = 0; for (int i = 0; i < nodes.length; i++) { conflicts += printList(i); } System.out.println("Total # of conflicts: " + conflicts); } // Print the list content private int printList(int index) { System.out.print("Index " + index + ": "); int totalConflicts = 0; if (nodes[index] == null) { System.out.println(" (0 conflicts), []"); } else { int conflicts = listSize(index) - 1; totalConflicts += conflicts; System.out.print(" (" + conflicts + " conflicts), ["); HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { System.out.print(currentNode.getKey() + ", "); currentNode = currentNode.getNext(); } System.out.println("]"); } return totalConflicts; } // Return how many elements are in the linked list private int listSize(int index) { if (nodes[index] == null) { return 0; } int count = 0; HashNode currentNode = (HashNode) nodes[index]; while (currentNode != null) { count++; currentNode = currentNode.getNext(); } return count; } // Hash the key private int hash(K key) { int hashCode = key.hashCode(); int index = hashCode % nodes.length; return Math.abs(index); } }