学步园

#include <iostream>
using namespace std;

class stack
{
private:
	int* data;
	int cur;
	int capacity;
public:
	stack(int cap = 100)
	{
		data = new int[cap];
		cur = -1;
		capacity = cap;
	}

	~stack()
	{
		delete[] data;
	}

	void push(int val)
	{
		data[++cur] = val;
	}

	void pop()
	{
		--cur;
	}

	int top()
	{
		return data[cur];
	}

	bool full()
	{
		return cur == capacity - 1;
	}

	bool empty()
	{
		return cur == -1;
	}
};

class Myqueue
{
private:
	stack a, b;

public:
	Myqueue()
	{

	}

	~Myqueue()
	{
		
	}
	
	void push(int val)
	{
		while (!b.empty())
		{
			a.push(b.top());
			b.pop();
		}
		if (!a.full())
		{
			a.push(val);
		}
	}

	void pop()
	{
		while (!a.empty())
		{
			b.push(a.top());
			a.pop();
		}
		if (!b.empty())
		{
			b.pop();
		}
	}

	int top()
	{
		while (!a.empty())
		{
			b.push(a.top());
			a.pop();
		}
		if (!b.empty())
		{
			return b.top();
		}
	}
};

int main(void)
{
	Myqueue q;

	q.push(1);
	q.push(2);
	q.push(3);
	cout<<q.top()<<endl;
	q.pop();
	cout<<q.top()<<endl;
	q.pop();
	q.push(4);
	cout<<q.top()<<endl;
	q.pop();
	

	return 0;
}