Queue.java

import java.util.NoSuchElementException;
import java.util.ArrayList;
import java.util.NoSuchElementException;
public class Queue<T> implements QueueADT<T> {
 private ArrayList<T> data;
 public Queue() {
 data = new ArrayList<T>();
 }

 public void enqueue(T item) {
 data.add(item);
 }

 public T dequeue() throws NoSuchElementException {
 T ret = data.get(0);
 data.remove(0);
 return ret;
 }

 public T front() throws NoSuchElementException {
 return data.get(0);
 }

 public Queue<T> clone() {
 Queue<T> ret = new Queue<T>();
 for(T i:data) {
 ret.enqueue(i);
 }
 return ret;
 }

 public int size() {
 return data.size();
 }

 public boolean isEmpty() {
 if(data.size() > 0) {
 return false;
 }
 return true;
 }

 public void clear() {
 data = new ArrayList<T>();
 }
 
 public String toString() {
 StringBuilder sb = new StringBuilder();
 for(T i:data) {
 sb.append(i.toString());
 }
 return sb.toString();
 }
}