BoolCalculate

#include <iostream>
#include <stack>

using namespace std;

string postfixC(string infix)
{
    string output = "";
    stack<char> operators;
    for (int i = 0; i < infix.length(); i++)
    {
        if (infix[i] == 't' || infix[i] == 'f')
        {
            output += infix[i];
        }
        else if (infix[i] == '(')
        {
            operators.push(infix[i]);
        }
        else if (infix[i] == ')')
        {
            while (operators.top() != '(')
            {

                output += operators.top();
                operators.pop();
            }
            operators.pop();
        }
        else if (infix[i] == '!')
        {
            operators.push(infix[i]);
        }
        else if (infix[i] == '*')
        {
            while (!operators.empty() && (operators.top() == '*' || operators.top() == '!'))
            {
                    output += operators.top();
                    operators.pop();
            }
            operators.push(infix[i]);
        }
        else if (infix[i] == '+')
        {
            while (!operators.empty() && (operators.top() == '*' || operators.top() == '!' || operators.top() == '+'))
            {
                    output += operators.top();
                    operators.pop();
            }
            operators.push(infix[i]);
        }
    }

    while (!operators.empty())
    {
        output += operators.top();
        operators.pop();
    }
    return output;
}

bool calculatePostfix(string postfix)
{
    stack<char> st;
    for (int i = 0; i < postfix.length(); i++)
    {
        if (postfix[i] == 't' || postfix[i] == 'f')
        {
            st.push(postfix[i]);
        }
        else if (postfix[i] == '*')
        {
            bool operandB = (st.top() == 't') ? true : false;
            st.pop();
            bool operandA = (st.top() == 't') ? true : false;
            st.pop();
            if (operandA && operandB)
            {
                st.push('t');
            }
            else
            {
                st.push('f');
            }
        }
        else if (postfix[i] == '+')
        {
            bool operandB = (st.top() == 't') ? true : false;
            st.pop();
            bool operandA = (st.top() == 't') ? true : false;
            st.pop();
            if (operandA || operandB)
            {
                st.push('t');
            }
            else
            {
                st.push('f');
            }
        }
        else if (postfix[i] == '!')
        {
            bool operand = (st.top() == 't') ? true : false;
            st.pop();
            if (!operand)
            {
                st.push('t');
            }
            else
            {
                st.push('f');
            }
        }
    }
    return (st.top() == 't');
}

int main()
{
    string expr;
    cout << "Enter expression: ";
    getline(cin, expr);
    if (calculatePostfix(postfixC(expr)))
    {
        cout << 't' << endl;
    }
    else
    {
        cout << 'f' << endl;
    }

    return 0;
}