/*
         VARIABLES

Variables are NOT ALLOWED until lab 7

const int x = 123;  // declares x, its value can never be changed
      int x = 123;  // creates variable x, gives it a first value
          x = 456;  // x must already exist as variable, give it new value
          x = 345 * y + z * z;   // so long as y and z are ints too
          x = x+1.0;  // increases value of x by 1
*/

/*
  I want a definite response of "yes" or "no", or to know invalid

  cout << "Please answer yes or no: ";
  const string reply = read_string();
  if (reply == "yes")
  { const bool answer = true;
    const bool valid = true; }
  else if (reply == "no")
  { const bool answer = false;
    const bool valid = true; }
  else
    const bool valid = false; 
  // valid and answer do not exist any more at this point
*/

/*
// corrected version
  cout << "Please answer yes or no: ";
  const string reply = read_string();
  bool answer, valid = false;
  if (reply == "yes")
  { answer = true;
    valid = true; }
  else if (reply == "no")
  { answer = false;
    valid = true; }

 // what if I say
   int x;
   x = x + 1;
 // value of x is unknown, can't rely on it being 1
*/

/*
// got three values x, y, z
// I want m to be the smallest of them

int min(int a, int b)
{ if (a < b)
    return a;
  return b; }

const int m = min(x, min(y, z));

or using variables

  int min = a;
  if (b < min)
    min = b;
  if (c < min)
    min = c;
*/

int day_of_year(int y, int m, int d)
{ int result = 0;
  if (m > 1)
    result = result + 31;
  if (m > 2)
    result = result + isleapyear(y) ? 29 : 28;
  if (m > 3)
    result = result + 31;
  if (m > 4)
    result = result + 30;
  if (m > 5)
    result = result + 31;
  if (m > 6)
    result = result + 30;
  if (m > 7)
    result = result + 31;
  if (m > 8)
    result = result + 31;
  if (m > 9)
    result = result + 30;
  if (m > 10)
    result = result + 31;
  if (m > 11)
    result = result + 30;
  return result + d; }