LeetCode 622 Java

[cedarparkfamily]

class MyCircularQueue {


final int[] a;

int front;
int rear = -1;
int len = 0;

// 初始化 循环queue
public MyCircularQueue(int k) { a = new int[k];}

public boolean enQueue(int val) {

if (!isFull()) {

/** _ _ _ _ _
* F
* R
* */

/** 用這種方式來定位 */
rear = (rear + 1) % a.length;
a[rear] = val;
len++;

return true;

} else {

return false;
}

}

public boolean deQueue() {

if (!isEmpty()) {

front = (front + 1) % a.length;

len--;

return true;

} else return false;

}

// 下面是常规的操作
public int Front() { return isEmpty() ? -1 : a[front];}

public int Rear() {return isEmpty() ? -1 : a[rear];}

public boolean isEmpty() { return len == 0;}

public boolean isFull() { return len == a.length;}
}

/**
* Your MyCircularQueue object will be instantiated and called as such:
* MyCircularQueue obj = new MyCircularQueue(k);
* boolean param_1 = obj.enQueue(value);
* boolean param_2 = obj.deQueue();
* int param_3 = obj.Front();
* int param_4 = obj.Rear();
* boolean param_5 = obj.isEmpty();
* boolean param_6 = obj.isFull();
*/