Merge pull request #1391 from rbshealy/master

Add nested linked list and node class to HashMap.java

DataStructures/HashMap/Hashing/HashMap.java

@@ -1,7 +1,6 @@
 package DataStructures.HashMap.Hashing;
 
-
-class HashMap {
+public class HashMap {
     private int hsize;
     private LinkedList[] buckets;
 
@@ -36,8 +35,114 @@ class HashMap {
     public void displayHashtable() {
         for (int i = 0; i < hsize; i++) {
             System.out.printf("Bucket %d :", i);
-            buckets[i].display();
+            System.out.println(buckets[i].display());
         }
     }
-
-}
+    
+    public static class LinkedList {
+    	private Node first;
+    	
+    	public LinkedList() {
+    		first = null;
+    	}
+    	
+    	public void insert(int key){
+    		if(isEmpty()) {
+    			first = new Node(key);
+    			return;
+    		}
+    		
+    		Node temp = findEnd(first);
+    		temp.setNext(new Node(key));
+    	}
+    	
+    	private Node findEnd(Node n) {
+    		if(n.getNext() == null) {
+    			return n;
+    		} else {
+    			return findEnd(n.getNext());
+    		}
+    	}
+    	
+    	public Node findKey(int key) {
+    		if(!isEmpty()) {
+    			return findKey(first, key);
+    		} else {
+    			System.out.println("List is empty");
+    			return null;
+    		}
+    		
+    	}
+    	
+    	private Node findKey(Node n, int key) {
+    		if(n.getKey() == key) {
+    			return n;
+    		} else if(n.getNext() == null) {
+    			System.out.println("Key not found");
+    			return null;
+    		} else {
+    			return findKey(n.getNext(),key);
+    		}
+    	}
+    	
+    	public void delete(int key) {
+    		if(!isEmpty()) {
+    			if(first.getKey() == key) {
+    				first = null;
+    			} else {
+    				delete(first,key);
+    			}
+    		} else {
+    			System.out.println("List is empty");
+    		}
+    	}
+    	
+    	private void delete(Node n, int key) {
+    		if(n.getNext().getKey() == key) {
+    			if(n.getNext().getNext() == null) {
+    				n.setNext(null);
+    			} else {
+    				n.setNext(n.getNext().getNext());
+    			}
+    		}
+    	}
+    	
+    	public String display() {
+    		return display(first);
+    	}
+    	
+    	private String display(Node n) {
+    		if(n == null) {
+    			return "null";
+    		} else {
+    			return n.getKey() + "->" + display(n.getNext());
+    		}
+    	}
+    	
+    	public boolean isEmpty() {
+    		return first == null;
+    	}
+    }
+    
+    public static class Node {
+    	private Node next;
+    	private int key;
+    	
+    	public Node(int key) {
+    		next = null;
+    		this.key = key;
+    	}
+    	
+    	public Node getNext() {
+    		return next;
+    	}
+    	
+    	public int getKey() {
+    		return key;
+    	}
+    	
+    	public void setNext(Node next) {
+    		this.next = next;
+    	}
+    }
+}