package test;
public class MyQueue<T> {
//initialize
T[] arr = null;
public MyQueue(){
arr = (T[])new Object[0];
}
// ADD/OFFER Func
public void add(T element) {
//create a new array 1 longer than the original one
T[] newArr = (T[])new Object[arr.length + 1];
//copy all element from arr to newArr
for(int i = 0; i < arr.length; i++) {
newArr[i] = arr[i];
}
//put the new element into the end of newArr
newArr[newArr.length - 1] = element;
//copy newArr to arr
arr = newArr;
}
// POLL/Remove Func
public T poll() {
//check first
if(arr.length == 0) {
throw new ArrayIndexOutOfBoundsException();
}
//create a newArr 1 shorter than arr
T[] newArr = (T[])new Object[arr.length - 1];
//copy all element from arr to the newArr(except the first one)
for(int i = 0; i < newArr.length; i++) {
newArr[i] = arr[i + 1];
}
//get the last element in arr
T ele = arr[0];
//copy newArr to arr
arr = newArr;
//return the last element
return ele;
}
// PEEL/ELEMENT Func
public T peek() {
//check first
if(arr.length == 0) {
throw new ArrayIndexOutOfBoundsException();
}
//return the last element in the array
return arr[0];
}
//ISEMPTY Func
public boolean isEmpty() {
return arr.length == 0;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
MyQueue ms = new MyQueue();
// 进队
ms.add(99);
ms.add(98);
ms.add(97);
ms.add(96);
ms.add("a");
ms.add("b");
ms.add("c");
// 出队
System.out.println(ms.poll());
System.out.println(ms.poll());
System.out.println(ms.poll());
System.out.println(ms.poll());
System.out.println(ms.poll());
System.out.println(ms.poll());
System.out.println(ms.isEmpty());
}
}
