队列——先进先出
队列的一个缺点——出队后的内存空间浪费了,不能二次利用
环形队列——解决以上缺点的队列,用过的内存空间可以重复利用
github: https://github.com/HITFishily/CandCPP/blob/master/ring_queue.h
代码:
#include <iostream>
using namespace std;
template<typename T> class CircleQueue
{
private:
unsigned int m_size;
int m_front;
int m_rear;
T* m_data;
public:
CircleQueue(unsigned int size)
{
m_front = 0;
m_rear = 0;
m_size = size + 1;
m_data = new T[m_size + 1];
}
~CircleQueue()
{
delete[] m_data;
}
bool isEmpty()
{
return m_front == m_rear;
}
bool isFull()
{
return m_front == (m_rear + 1) % m_size;
}
void push(T data)
{
if (isFull())
{
throw "The queue is full,cannot keep pushing.";
}
m_data[m_rear] = data;
m_rear = (m_rear + 1) % m_size;
}
void pop()
{
if (isEmpty())
{
throw new exception("The queue is empty,cannot keep poping.");
}
m_front = (m_front + 1) % m_size;
}
void popall()
{
if (isEmpty())
{
throw new exception("The queue is empty,cannot keep poping.");
}
while (m_front != m_rear)
m_front = (m_front + 1) % m_size;
}
T top()
{
if (isEmpty())
{
throw new exception("The queue is empty,cannot access the top element.");
}
return m_data[m_front];
}
};