package queue;

import java.util.ArrayList;

import java.util.NoSuchElementException;

public class MyQueue<T> {

ArrayList<T> arr = new ArrayList<T>();

int size = 0;

public MyQueue() {

}

public int size() {

return size;

}

public boolean isEmpty() {

if (size == 0) {

return true;

}

return false;

}

public void add(T element) {

arr.add(element);

size++;

}

public T remove() {

T element = arr.get(0);

if (isEmpty()) {

throw new NoSuchElementException();

}

arr.remove(0);

size--;

return element;

}

public T poll() {

if (isEmpty()) {

return null;

}

T element = arr.get(0);

arr.remove(0);

size--;

return element;

}

public T peek() {

if (isEmpty()) {

return null;

}

return arr.get(0);

}

public T element() {

if (isEmpty()) {

throw new NoSuchElementException();

}

return arr.get(0);

}

public String toString() {

if (isEmpty()) {

return null;

}

StringBuilder str = new StringBuilder("[");

for (int i = 0; i < size - 1; i++) {

str.append(arr.get(i));

str.append(", ");

}

str.append(arr.get(size - 1));

str.append("]");

return str.toString();

}

}