Program converts expressions to postfix form

hw6/from infix to postfix/from infix to postfix.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.27703.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "from infix to postfix", "from infix to postfix\from infix to postfix.vcxproj", "{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Debug|x64.ActiveCfg = Debug|x64
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Debug|x64.Build.0 = Debug|x64
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Debug|x86.ActiveCfg = Debug|Win32
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Debug|x86.Build.0 = Debug|Win32
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Release|x64.ActiveCfg = Release|x64
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Release|x64.Build.0 = Release|x64
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Release|x86.ActiveCfg = Release|Win32
+		{54D5BC53-220D-4FE3-BB72-1FF3E987C3AD}.Release|x86.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {05DC8ABC-44E6-489E-859E-8BB93557CE7C}
+	EndGlobalSection
+EndGlobal

hw6/from infix to postfix/from infix to postfix/Element.cpp

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+#include "Element.h"
+
+Element::Element(char data = '\0')
+{
+	this->data = data;
+	this->next = nullptr;
+}
+
+Element::~Element()
+{
+	this->data = '\0';
+	this->next = nullptr;
+}

hw6/from infix to postfix/from infix to postfix/Element.h

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+#pragma once
+
+struct Element
+{
+	Element(char data);
+	~Element();
+	char data;
+	Element* next;
+};

hw6/from infix to postfix/from infix to postfix/Infix to postfix.cpp

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+#include "Infix to postfix.h"
+
+bool isOperator(char const symbol);
+bool isRoundBracket(char const symbol);
+void doIfOperator(Stack & s, string & toPostrix, int & currentIndex, char const currentSymbol);
+int doIfRoundBracket(Stack & s, string & toPostfix, int & currentIndex, char const currentSymbol);
+int popAllOperators(Stack & s, string & toPostfix, int & currentIndex);
+bool isPlusOrMinus(char const symbol);
+bool isMultOrDiv(char const symbol); 
+
+int infixToPostfix(string const & infix, string & toPostfix)
+{
+	Stack s;
+	int currentIndex = 0;
+	for (int i = 0; i < (int)infix.size(); ++i)
+	{
+		if (!isOperator(infix[i]) && !isRoundBracket(infix[i]))
+		{
+			toPostfix += infix[i];
+			++currentIndex;
+		}
+		else
+		{
+			if (isOperator(infix[i]))
+			{
+				doIfOperator(s, toPostfix, currentIndex, infix[i]);
+			}
+			else
+			{
+				if (doIfRoundBracket(s, toPostfix, currentIndex, infix[i]) == -1)
+				{
+					cout << "Infix expression is incorrect" << endl;
+					return -1;
+				}
+			}
+		}
+	}
+	while (!s.isEmpty())
+	{
+		if (popAllOperators(s, toPostfix, currentIndex) == -1)
+		{
+			return -1;
+		}
+	}
+	return 0;
+}
+
+bool isOperator(char const symbol)
+{
+	return (symbol == '+' || symbol == '-' || symbol == '*' || symbol == '/');
+}
+
+bool isRoundBracket(char const symbol)
+{
+	return (symbol == '(' || symbol == ')');
+}
+
+void doIfOperator(Stack & s, string & toPostfix, int & currentIndex, char const currentSymbol)
+{
+	if (s.isEmpty())
+	{
+		s.push(currentSymbol);
+	}
+	else
+	{
+		if (isMultOrDiv(currentSymbol) && isPlusOrMinus(s.peek()) || s.peek() == ')') 
+		{
+			s.push(currentSymbol);
+		}
+		else if (s.peek() == '(')
+		{
+			s.push(currentSymbol);
+		}
+		else 
+		{
+			// ������� ������ ����� ��� ���, ��������� ������� �� ����� - �������� ��� ������
+			// ������� ������� ���� ��� �����, ��������� ������� �� ����� - ��������
+			toPostfix += s.peek();
+			++currentIndex;
+			s.pop();
+			s.push(currentSymbol);
+		}
+	}
+}
+
+int doIfRoundBracket(Stack & s, string & toPostfix, int & currentIndex, char const currentSymbol)
+{
+	if (currentSymbol == ')' && s.isEmpty())
+	{
+		return -1;
+	}
+	else if (currentSymbol == ')' && isOperator(s.peek()))
+	{
+		toPostfix += s.peek();
+		++currentIndex;
+		s.pop();
+		if (s.peek() == '(')
+		{
+			s.pop();
+		}
+	}
+	else
+	{
+		// ���� ������ �������, �� ������ ������ �� � ����
+		s.push(currentSymbol);
+	}
+	return 0;
+}
+
+int popAllOperators(Stack & s, string & toPostfix, int & currentIndex)
+{
+	if (isRoundBracket(s.peek()))
+	{
+		return -1;
+	}
+	toPostfix += s.peek();
+	++currentIndex;
+	s.pop();
+	return 0;
+}
+
+bool isPlusOrMinus(char const symbol)
+{
+	return (symbol == '+' || symbol == '-');
+}
+
+bool isMultOrDiv(char const symbol)
+{
+	return (symbol == '*' || symbol == '/');
+}

hw6/from infix to postfix/from infix to postfix/Infix to postfix.h

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+#pragma once
+#include <string>
+#include <iostream>
+#include "Stack.h"
+
+using namespace std;
+
+int infixToPostfix(string const & infix, string & toPostfix);

hw6/from infix to postfix/from infix to postfix/Stack.cpp

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+#include "Stack.h"
+#include "Element.h"
+
+Stack::Stack()
+{
+	head = nullptr;
+}
+
+Stack::~Stack()
+{
+	auto* temp = head;
+	while (!isEmpty())
+	{
+		temp = head;
+		head = temp->next;
+		temp->next = nullptr;
+		delete temp;
+		temp = nullptr;
+	}
+}
+
+void Stack::push(char data)
+{
+	auto* newElement = new Element(data);
+	if (!isEmpty())
+	{
+		newElement->next = head;
+	}
+	head = newElement;
+}
+
+int Stack::pop()
+{
+	if (!isEmpty())
+	{
+		auto* temp = head->next;
+		head->next = nullptr;
+		delete head;
+		head = nullptr;
+		head = temp;
+		return 0;
+	}
+	else
+	{
+		return -1;
+	}
+}
+
+char Stack::peek()
+{
+	if (!isEmpty())
+	{
+		return head->data;
+	}
+	else
+	{
+		cout << "Stack is empty\n";
+		return '\0';
+	}
+}
+
+bool Stack::isEmpty()
+{
+	return head == nullptr;
+}

hw6/from infix to postfix/from infix to postfix/Stack.h

@@ -0,0 +1,28 @@
+#pragma once
+#include <iostream>
+
+using namespace std;
+
+struct Element;
+
+struct Stack
+{
+	// �����������
+	Stack();
+	// ����������
+	~Stack();
+	// ����������� �����������
+
+	// �������� ������������
+
+	// ���������� �������� � ������
+	void push(char data);
+	// �������� �������� �� ������
+	int pop();
+	// ���������� �� �������� �������
+	char peek();
+	// ��������� �������� �� ���� ������
+	bool isEmpty();
+private:
+	Element * head;
+};