Infix to Postfix C++ Program

infix_to_postfix.cpp

#include<bits/stdc++.h>
using namespace std;

//Assuming each operand and operator is of 1 character instead of multiple characters

bool IsOpeningParenthesis(char optr)
{
	if(optr == '(' || optr == '{' || optr == '[')
		return true;
	else
	 return false;
}
bool IsClosingParenthesis(char optr)
{
	if(optr == ')' || optr == '}' || optr == ']')
		return true;
	else
	 return false;
}
bool HasHigherPrecedence(char top,char curr_exp)
{
	map<char,int> precede_map;
	precede_map['+']= 0;
	precede_map['-']= 0;
	precede_map['*']= 1;
	precede_map['/']= 1;
	
	if(precede_map[top] >= precede_map[curr_exp])
		return true;
	else
		return false;
}

string InfixToPostfix(string exp)
{
	stack<int> s;
	string post;
	for(int i = 0;i< exp.length();i++)
	{
		if(isalnum(exp[i]))
			post.push_back(exp[i]);
		else if(!IsOpeningParenthesis(exp[i]) && !IsClosingParenthesis(exp[i]))
		{
			while(!s.empty() && !IsOpeningParenthesis(s.top()) && HasHigherPrecedence(s.top(),exp[i]))
			{
				post.push_back(s.top());
				s.pop();
			}
			s.push(exp[i]);
		}
		else if(IsOpeningParenthesis(exp[i]))
			s.push(exp[i]);
		else if(IsClosingParenthesis(exp[i]))
		{
			while(!s.empty() && !IsOpeningParenthesis(s.top()))
			{
				post.push_back(s.top());
				s.pop();
			}
			s.pop();
		}
	}
		while(!s.empty())
		{
			post.push_back(s.top());
			s.pop();
		}
	return post;	
}

int main()
{
	string exp;
	getline(cin,exp);
	cout<<InfixToPostfix(exp);
}