public class JavaDS { public static void main(String[] args){ //stack tester Stack STACK1; STACK1 = new Stack(); STACK1.push(23); STACK1.push(11); STACK1.push(2); STACK1.pop(); STACK1.pop(); STACK1.pop(); //queue tester Queue QUEUE1; QUEUE1 = new Queue(); QUEUE1.push(23); QUEUE1.push(11); QUEUE1.push(2); QUEUE1.display(); QUEUE1.pop(); QUEUE1.display(); QUEUE1.pop(); QUEUE1.display(); QUEUE1.pop(); QUEUE1.display(); //linkedlist teseter LinkedList list = new LinkedList(); list.addToTail(5); list.addToTail(2); list.addToTail(-2); System.out.println(list.removeHead()+ " Is the head, and it's been removed"); System.out.println(list.getHead()+" This is the new head"); list.addToTail(3); list.addToTail(1000); System.out.println(list.contains(1000)); //tree tester Tree tree = new Tree(); int[] items = {5, 8, 7, 1, 9, 3, 0, 4, 6, 2}; for (int i : items) tree.addChild(i); System.out.println("Is it contain 3: " + tree.contains(3)); tree.display(); //hashtable tester HashTable hashTable = new HashTable(); // Put some key values. hashTable.insert("cat","1"); hashTable.insert("cat","2"); hashTable.insert("dog","3"); hashTable.remove("cat"); System.out.println(hashTable.retrieve("dog")); } }