postfix-calculator/stack.cpp at main · kox13/postfix-calculator · GitHub

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#include "stack.h"

Stack::~Stack()
{
	clear();
}

void Stack::push(const char* token)
{
	Node* node = new Node(token);

	if (!empty())
	{
		node->next = m_Top;
		m_Top->prev = node;
	}

	m_Top = node;
}

void Stack::push(int value)
{
	Node* node = new Node(value);

	if (!empty())
	{
		node->next = m_Top;
		m_Top->prev = node;
	}

	m_Top = node;
}

void Stack::push(Token* token)
{
	Node* node = new Node(token);

	if (!empty())
	{
		node->next = m_Top;
		m_Top->prev = node;
	}

	m_Top = node;
}

Token* Stack::popptr()
{
	if (empty()) return nullptr;

	Node* ptr = m_Top;
	Token* token = ptr->data;

	ptr->data = nullptr;
	m_Top = ptr->next;
	delete ptr;

	return token;
}

void Stack::pop()
{
	if (empty()) return;

	Node* ptr = m_Top;
	m_Top = ptr->next;
	delete ptr;
}

void Stack::clear()
{
	Node* ptr = m_Top;
	Node* tmp;

	while (ptr)
	{
		tmp = ptr->next;
		delete ptr;
		ptr = tmp;
	}

	m_Top = nullptr;
}

void Stack::reverse()
{
	if (empty()) return;

	Node* ptr = m_Top;
	Node* tmp = nullptr;

	while (ptr)
	{
		tmp = ptr->next;
		ptr->next = ptr->prev;
		ptr->prev = tmp;
		if (tmp) ptr = tmp;
		else break;
	}

	m_Top = ptr;
}

void Stack::movetop(Stack& dest, Stack& src)
{
	if (src.empty()) return;

	dest.push(src.popptr());
}

std::ostream& operator<<(std::ostream& out, Stack& stack)
{
	Node* ptr = stack.m_Top;

	while (ptr)
	{
		out << *ptr->data << " ";
		ptr = ptr->next;
	}

	return out;
}