#!/usr/bin/perl

# is Persian year y a leap year in the Persian calendar?
sub is_leap_year {
  my $y = shift;
  my $a = ($y + 2345) % 2820;

  return 1 if $a == 2819;

  my $b = $a % 128;
  my $c;
  if ($b < 29) { $c = $b }
  else { $c = ($b - 29) % 33 }
  return 0 if $c == 0;
  return 1 if $c %4 == 0;
  return 0;
}

# Is Gregorian year g a leap year ** in the Persian calendar **?
sub is_gregorian_leap_year {
  my $g = shift;
  return is_leap_year($g - 2008 + 1386);
}

my $prev;
for (1979 .. 2028) {
  my $is = is_g_leap_year($_);
  printf "%4d %s\n", $_, $is ? "*" : " ";
  die if $is && $prev;
  $prev = $is;
#  $ct++ if $is;
}
#print ">> $ct\n";