641_design_circular_deque.java

class MyCircularDeque {

    int[] queue;
    int front;
    int rear;
    int size;
    int capacity;

    public MyCircularDeque(int k) {
        queue = new int[k];
        front = 0;
        rear = k - 1;
        size = 0;
        capacity = k;
    }
    
    public boolean insertFront(int value) {
        if (isFull()) return false;
        front = (front - 1 + capacity) % capacity;
        queue[front] = value;
        size++;
        return true;
    }
    
    public boolean insertLast(int value) {
        if (isFull()) return false;
        rear = (rear + 1) % capacity;
        queue[rear] = value;
        size++;
        return true;
    }
    
    public boolean deleteFront() {
        if (isEmpty()) return false;
        front = (front + 1) % capacity;
        size--;
        return true;
    }
    
    public boolean deleteLast() {
        if (isEmpty()) return false;
        rear = (rear - 1 + capacity) % capacity;
        size--;
        return true;
    }
    
    public int getFront() {
        if (isEmpty()) return -1;
        return queue[front];
    }
    
    public int getRear() {
        if (isEmpty()) return -1;
        return queue[rear];
    }
    
    public boolean isEmpty() {
        return size == 0;
    }
    
    public boolean isFull() {
        return size == capacity;
    }
}