Calculator

 /*
    To calculate speed do Distance divided by time
  */
#include <iostream>

using namespace std;

bool
ReDo ()
{
  string YesOrNo;
  cout << "Want to go back to main?\n";
  cin >> YesOrNo;
  if (YesOrNo == "Y" || YesOrNo == "y" || YesOrNo == "Yes"
      || YesOrNo == "yes")
    {
      return true;
    }
  else if (YesOrNo == "N" || YesOrNo == "n" || YesOrNo == "No"
       || YesOrNo == "no")
    {
      return false;
    }
  else
    {
      ReDo ();
    }
}

bool
USD ()
{
  string Type;
  cout << "To?\n";
  cout << "CAD (Canadian currency)\n" << "Pound (British currency)\n";
  cin >> Type;
  if (Type == "CAD" || Type == "cad")
    {
      int USDCASH;
      int CADCASH;
      cout << "Enter USD amount: ";
      cin >> USDCASH;
      CADCASH = (USDCASH / 1.33);
      cout << CADCASH << " CAD\n";
      return true;
    }
  else if (Type == "Pound" || Type == "pound")
    {
      int USDCASH;
      int POUNDCASH;
      cout << "Enter USD amount: ";
      cin >> USDCASH;
      POUNDCASH = (USDCASH * 0.77);
      cout << POUNDCASH << " POUNDS\n";
    }
  else
    {
      return false;
    }
}

void
Cash ()
{
  string Type;
  cout << "Start from?\n";
  cout << "USD\n" << "CAD (Canadian currency)\n" <<
    "Pound (British currency)\n";
  cin >> Type;
  if (Type == "USD" || Type == "usd")
    {
      if (USD () == true)
    {
      cout << "Successful!\n";
    }
      else
    {
      cout << "UnSuccessful.\n";
    }
    }
}

int
main ()
{
  string Choice;
  cout << "Which calculator?\n";
  cout << "Speed\n" << "Cash\n" << "Normal calculator\n";
  cin >> Choice;
  if (Choice == "Cash" || Choice == "cash")
    {
      Cash ();
    }
    if (ReDo() == true) {
        main();
    } else {
        cout << "Goodbye!\n";
    }
}