[Leetcode]设计循环队列

题目

 

代码

class MyCircularQueue {
public:
    /** Initialize your data structure here. Set the size of the queue to be k. */
    MyCircularQueue(int k):array(k),pre(0),rail(0),numbers(0) {

    }

    /** Insert an element into the circular queue. Return true if the operation is successful. */
    bool enQueue(int value) {
        if(numbers==array.size())
            return false;
        array[rail]=value;
        rail=(rail+1)%array.size();
        numbers++;
        return true;
    }

    /** Delete an element from the circular queue. Return true if the operation is successful. */
    bool deQueue() {
      if(numbers<=0)
          return false;
      pre=(pre+1)%array.size();
      numbers--;
      return true;
    }

    /** Get the front item from the queue. */
    int Front() {
        if(isEmpty())
            return -1;
        return array[pre];
    }

    /** Get the last item from the queue. */
    int Rear() {
        if(isEmpty())
            return -1;
        int pos=(rail-1+array.size())%array.size();
        std::cout<<"weizhi:"<<abs(pos);
        return array[abs(pos)];
    }

    /** Checks whether the circular queue is empty or not. */
    bool isEmpty() {
        if(pre==rail&&numbers==0)
            return true;
        return false;
    }

    /** Checks whether the circular queue is full or not. */
    bool isFull() {
        if(numbers==array.size())
            return true;
        return false;
    }
private:

    int numbers;//已经存储的数值
    int pre;
    int rail;
    vector<int> array;

};

/**
 * 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();
 */