包含min函数的桟

题目描述

#include <iostream>
#include <stack>
#include <assert.h>

using namespace std;

template<typename T> class StackWithMin
{
public:
	StackWithMin(void){}
	virtual ~StackWithMin(void){}

	T& top(void);
	const T& top(void) const;

	void push(const T& value);
	void pop (void);

	const T& min(void) const;

	bool empty() const;

	size_t size() const;

private:
	stack<T> m_data;
	stack<T> m_min;
};

template<typename T> void StackWithMin<T>::push(const T& value)
{
	m_data.push(value);

	if(m_min.size() == 0 || m_min.top() > value)
		m_min.push(value);
	else
		m_min.push(m_min.top());
}

template<typename T> void StackWithMin<T>::pop()
{
	assert(m_min.size() > 0 &&  m_data.size() > 0);

	m_min.pop();
	m_data.pop();
	
}

template<typename T> const T&  StackWithMin<T>::min() const
{
	assert(m_min.size() > 0 &&  m_data.size() > 0);

	return m_min.top();
}

template<typename T> T& StackWithMin<T>::top()
{
	return m_data.top();
}

template<typename T> const T& StackWithMin<T>::top() const
{
	return m_data.top();
}

template<typename T> bool StackWithMin<T>::empty() const
{
	return m_data.empty();
}

template<typename T> size_t StackWithMin<T>::size() const
{
	return m_data.size();
}

void Test(char* testName, const StackWithMin<int>& stack, int expected)
{
    if(testName != NULL)
        printf("%s begins: ", testName);

    if(stack.min() == expected)
        printf("Passed.\n");
    else
        printf("Failed.\n");
}

int main(int argc, char* argv[])
{
    StackWithMin<int> stack;

    stack.push(3);
    Test("Test1", stack, 3);

    stack.push(4);
    Test("Test2", stack, 3);

    stack.push(2);
    Test("Test3", stack, 2);

    stack.push(3);
    Test("Test4", stack, 2);

    stack.pop();
    Test("Test5", stack, 2);

    stack.pop();
    Test("Test6", stack, 3);

    stack.pop();
    Test("Test7", stack, 3);

    stack.push(0);
    Test("Test8", stack, 0);

    return 0;
}