[DataStructures] 큐(Queue) - 동적 큐(DynamicQueue)

큐(Queue) - 동적 큐(DynamicQueue)

- 큐의 수용량이 초과 되면 자동으로 배열의 크기를 늘린다

1. 구현

1) 초기화

int rear = -1; int front = 0; int currentSize = 0; private int[] queueArr; private int capacity = 2; public DynamicQueue(){ this.queueArr = new int[capacity]; }

- 동적으로 늘어날 것을 감안하여 사이즈 지정

2) enQueue(), isQueueFull()

public void enqueue(int element){ if(isQueueFull()){ System.out.println("Queue is full"); increaseCapacity(); } rear++; if(rear == capacity){ rear = 0; } currentSize++; this.queueArr[rear] = element; System.out.println("adding:"+element); System.out.println("rear:"+rear); } public boolean isQueueFull(){ return(currentSize == capacity); }  

3) deQueue(), isQueueEmpty()

public void dequeue(){ if(isQueueEmpty()){ System.out.println("Queue is empty"); }else{ front++; if(front > queueArr.length-1){ System.out.println("dequeue:"+this.queueArr[front-1]); front = 0; }else{ System.out.println("dequeue:"+this.queueArr[front-1]); } currentSize--; System.out.println("front:"+front); } } public boolean isQueueEmpty(){ return(currentSize == 0); }  

4) increaseCapacity()

public void increaseCapacity(){ this.capacity = capacity * 2; int[] newArry = new int[capacity]; for(int i = 0; i<currentSize; i++){ newArry[i] = queueArr[i]; } this.queueArr = newArry; System.out.println("increase Size: "+this.queueArr.length); this.rear = currentSize-1; }  

5) main()

public static void main(String[]args){ DynamicQueue qq = new DynamicQueue(); qq.enqueue(1); qq.enqueue(2); qq.enqueue(3); qq.dequeue(); qq.dequeue(); qq.dequeue(); qq.enqueue(4); qq.dequeue(); qq.enqueue(5); qq.enqueue(6); }