#!/usr/bin/perl -w
# varint.pl - Don Yang (uguu.org)
#
# 04/26/08

use strict;

# Encode number to variable length string
sub Encode($)
{
   my ($number) = @_;
   my $str = chr(35 + ($number % 57));
   for($number = int($number / 57); $number > 0; $number = int($number / 19))
   {
      $str = chr(93 + ($number % 19)) . $str;
   }
   return $str;
}

# Decode number from variable length string
sub Decode($)
{
   my @code = unpack 'C*', $_[0];
   my $number = 0;
   for(my $i = 0; $i < $#code; $i++)
   {
      $number = $number * 19 + $code[$i] - 93;
   }
   $number = $number * 57 + $code[$#code] - 35;
   return $number;
}

# Test conversion
for(my $i = 0; $i < 100000; $i++)
{
   my $j = Decode(Encode($i));
   die if $i != $j;
}