designCircularQueue.cpp

// Source: https://leetcode.com/problems/design-circular-queue/
// Author: Miao Zhang
// Date:   2021-02-25

class MyCircularQueue {
public:
    MyCircularQueue(int k) : q_(k) {

    }

    bool enQueue(int value) {
        if (isFull()) return false;
        q_[(front + size_) % q_.size()] = value;
        size_++;
        return true;
    }

    bool deQueue() {
        if (isEmpty()) return false;
        front = (front + 1) % q_.size();
        size_--;
        return true;
    }

    int Front() {
        return isEmpty() ? -1 : q_[front];
    }

    int Rear() {
        return isEmpty() ? -1 : q_[(front + size_ - 1) % q_.size()];
    }

    bool isEmpty() {
        return size_ == 0;
    }

    bool isFull() {
        return size_ == q_.size();
    }

private:
    vector<int> q_;
    int front = 0;
    int size_ = 0;
};

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