循环队列的复习

struct MyQueue { //循环队列需要少用一个
    int que[1000000], head, tail, MXSIZE;
    void init() {
        MXSIZE = 1000000; // 1e6
        head = tail = 0;
    }
    bool isEmpty() {
        return head == tail;
    }
    bool isFull() {
        return (tail + 1) % MXSIZE == head;
    }
    void add_back(int val) {
        if (isFull()) assert(false);
        que[tail] = val;
        tail = (tail + 1) % MXSIZE;
    }
    int del_front() {
        if (isEmpty()) assert(false);
        int cur = que[head];
        head = (head + 1) % MXSIZE;
        return cur;
    }
} que;