用数组实现队列

class Queue {
    int volume = 8;
    int _size = 0;
    int back = 0;
    int front = 0;
    int *data = nullptr;

    void grow() {
        int *temp = new int[2 * volume];
        for (int i = 0; i < volume; ++i) {
            temp[i] = data[(front + i) % volume];
        }
        delete[]data;
        data = temp;
        volume *= 2;
    }

public:
    Queue() {
        data = new int[volume];
    }

    void push(int value) {
        ++_size;
        data[back] = value;
        if (_size == volume) {
            grow();
        }
        back = (back + 1) % volume;
    }

    int pop() {
        if (empty())
            return -1;
        --_size;
        int temp=data[front];
        front=(front+1)%volume;
        return temp;
    }

    bool empty() const {
        return _size == 0;
    }

    bool size() const {
        return _size;
    }
};