c++环形队列
#pragma once#include <iostream>
#include <vector>/// <summary>
/// - 环形队列
/// - 不是线程安全
/// </summary>
/// <typeparam name="T"></typeparam>
template <typename T>
class CircularQueue
{int rear, front;int size;T* arr = nullptr;int _len = 0;
public:CircularQueue(int s){front = rear = -1;size = s;arr = new T[s];_len = 0;}~CircularQueue() {if (arr){delete[]arr;}};bool enQueue(T value){if ((front == 0 && rear == size - 1) ||((rear + 1) % size == front)){printf("\nQueue is Full");return false;}_len++;if (front == -1){front = rear = 0;arr[rear] = value;}else if (rear == size - 1 && front != 0){rear = 0;arr[rear] = value;}else{rear++;arr[rear] = value;}return true;};bool deQueue(T* val = nullptr) {if (front == -1){printf("\nQueue is Empty");return false;}_len--;T data = arr[front];arr[front] = -1;if (front == rear){front = -1;rear = -1;}else if (front == size - 1)front = 0;elsefront++;if (val){*val = data;}return true;};void autoQueue(T value) {while (enQueue(value) == false){deQueue();}};int len(){return _len;};std::vector<T> list(){std::vector<T> vals;if (front == -1){return vals;}if (rear >= front){for (int i = front; i <= rear; i++){vals.push_back(arr[i]);}}else{for (int i = front; i < size; i++){vals.push_back(arr[i]);}for (int i = 0; i <= rear; i++){vals.push_back(arr[i]);}}return vals;}void displayQueue() {std::vector<T> ls = list();printf("\n displayQueue: ");for (size_t i = 0; i < ls.size(); i++){printf("%d ", ls[i]);}printf("\n");};
};//int main()
//{
// CircularQueue<int> q(5);
// q.autoQueue(14);
// q.autoQueue(22);
// q.autoQueue(13);
// q.autoQueue(-6);
//
// q.displayQueue();
//
// q.autoQueue(9);
// q.autoQueue(20);
// q.autoQueue(5);
//
// q.displayQueue();
//
// q.autoQueue(20);
//
// q.displayQueue();
// return 0;
//}
