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infixToPostFix.h
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infixToPostFix.h
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// Header file: infixToPostFix.h
#ifndef H_infixToPostFix
#define H_infixToPostFix
#include "myStack.h"
class infixToPostfix
{
public:
infixToPostfix();
~infixToPostfix();
infixToPostfix(const string& infix);
void getInfix(std::string input);
string getInfx() const;
string getPfx() const;
void showInfix() const;
void showPostfix() const;
bool isOperator(char c);
bool precedence(char op1, char op2);
void convertToPostfix();
private:
stackType<char> stack;
std::string infx;
std::string pfx;
};
infixToPostfix::~infixToPostfix() {
// Destructor
}
infixToPostfix::infixToPostfix() {
this->infx = "";
}
infixToPostfix::infixToPostfix(const string& infix) {
this->infx = infix;
convertToPostfix();
}
bool infixToPostfix::isOperator(char c) {
return c == '+' || c == '-' || c == '*' || c == '/' || c == '^';
} // end isOperator
bool infixToPostfix::precedence(char op1, char op2) {
int prec1, prec2;
// Assigning precedence value to operator 1
if (op1 == '+' || op1 == '-')
prec1 = 1;
else if (op1 == '*' || op1 == '/')
prec1 = 2;
else
prec1 = 0;
// Assigning precedence value to operator 2
if (op2 == '+' || op2 == '-')
prec2 = 1;
else if (op2 == '*' || op2 == '/')
prec2 = 2;
else
prec2 = 0;
return prec1 >= prec2;
}
void infixToPostfix::getInfix(std::string input)
{
this->infx = input;
convertToPostfix();
} // end getInfix
// Getters
string infixToPostfix::getPfx() const {
return this->pfx;
} // end getPfx
string infixToPostfix::getInfx() const {
return this->infx;
}
// end getters
// Print Functions
void infixToPostfix::showInfix() const {
std::cout << "Infix: " << this->infx << std::endl;
} // end showInfix
void infixToPostfix::showPostfix() const {
std::cout << "Postfix: " << this->pfx << std::endl;
} // end showPostFix
// End print functions
// Main function for converting the infix to post fix
void infixToPostfix::convertToPostfix() {
stackType<char> stack;
for (int i = 0; i < this->infx.length(); i++) {
char sym = this->infx[i];
if (isalnum(sym)) {
this->pfx += sym;
}
else if (isOperator(sym)) {
while (!stack.isEmptyStack() && precedence(stack.top(), sym))
{
this->pfx += stack.top();
stack.pop();
}
stack.push(sym);
}
else if (sym == '(') {
stack.push(sym);
}
else if (sym == ')') {
while (!stack.isEmptyStack() && stack.top() != '(') {
this->pfx += stack.top();
stack.pop();
}
stack.pop();
}
}
while (!stack.isEmptyStack()) {
this->pfx += stack.top();
stack.pop();
}
} // end convertToPostFix
#endif