#include <iostream>
#include <cstdlib>
#include <cctype>
using namespace std;

class Money
{
public:
  friend bool operator >(const Money& amount1, const Money& amount2);
  friend bool operator >=(const Money& amount1, const Money& amount2);
  Money(long dollars, int cents);
  Money(long dollars);
  Money( );
  int percent(int percent_figure) const;
  friend istream& operator >>(istream& ins, Money& amount);
  friend ostream& operator <<(ostream& outs, const Money& amount);

private:
  long all_cents;
};

int digit_to_int(char c);

int main( ){
  Money amount1, amount2;
  int percent;

  cout << "Enter two amounts of money using dollar sign and decimal point ";
  cout << "(e.g., $12.57)" << endl << endl;

  cout << "First amount: ";
  cin >> amount1;
  cout << "Second amount: ";
  cin >> amount2;

  // Test > and >=
  if (amount1 > amount2)
    cout << amount1 << " > " << amount2 << endl;
  else if (amount1 >= amount2)
    cout << amount1 << " = " << amount2 << endl;
  else
    cout << amount1 << " < " << amount2 << endl;

  // Test percent
  cout << endl << "Enter a percent (0-100): ";
  cin >> percent;
  cout << percent << "% of " << amount1 << " is " << amount1.percent(percent);

  cout << endl << endl << "Bye!" << endl;
  system("pause");
}

//Uses iostream, cctype, cstdlib:
istream& operator >>(istream& ins, Money& amount){
  char one_char, decimal_point, digit1, digit2; //digits for the amount of cents
  long dollars;
  int cents;
  bool negative; //set to true if input is negative.

  ins >> one_char;
  if (one_char == '-'){
    negative = true;
    ins >> one_char; //read '$'
    }
  else
    negative = false; //if input is legal, then one_char == '$'

  ins >> dollars >> decimal_point >> digit1 >> digit2;
  if (one_char != '$' || decimal_point != '.' || !isdigit(digit1) || !isdigit(digit2)){
    cout << "Error illegal form for money input\n";
    exit(1);
    }

    cents = digit_to_int(digit1)*10 + digit_to_int(digit2);
    amount.all_cents = dollars*100 + cents;
    if (negative)
      amount.all_cents = -amount.all_cents;
    return ins;
}

int digit_to_int(char c){
  return (int(c) - int('0'));
}

ostream& operator <<(ostream& outs, const Money& amount){
  long positive_cents, dollars, cents;
  positive_cents = labs(amount.all_cents);
  dollars = positive_cents/100;
  cents = positive_cents%100;

  if (amount.all_cents < 0)
    outs << "-$" << dollars << '.';
  else
    outs << "$" << dollars << '.';

  if (cents < 10)
    outs << '0';
  outs << cents;
  return outs;
}

Money::Money(long dollars, int cents){
  if(dollars*cents < 0) //If one is negative and one is positive
    {
    cout << "Illegal values for dollars and cents.\n";
    exit(1);
    }
  all_cents = dollars*100 + cents;
}

int Money::percent(int percent_figure) const{
  cout << amount1(percent_figure/100));
}

Money::Money(long dollars) : all_cents(dollars*100){/*Body intentionally blank.*/}
Money::Money() : all_cents(0){/*Body intentionally blank.*/}
bool operator >(const Money& amount1, const Money& amount2){/*Body intentionally blank.*/}
bool operator >=(const Money& amount1, const Money& amount2){/*Body intentionally blank.*/}

int Money::percent( int percent_figure )
{
  return all_cents*percent_figure/100;
}

double Money::percent(double percent_figure) const{
  cout.setf(ios::fixed);
  cout.setf(ios::showpoint);
  cout.precision(2);
  return ((all_cents*(percent_figure/100))/100);
  }