#!/usr/bin/perl -w
# generate_symbol_map.pl - Don Yang (uguu.org)
#
# 10/01/09

use strict;

# Count all symbols
my %symbols;
while(my $line = <>)
{
   foreach ($line =~ /(\S+)/g)
   {
      $symbols{$_}++;
   }
}

# Output replacement symbols by count
my $index = 0;
my $dict = join '', ('a' .. 'z', 'A' .. 'Z', '0' .. '9');
foreach my $i (sort {$symbols{$a} != $symbols{$b}
                        ? $symbols{$b} <=> $symbols{$a} : $a cmp $b}
               keys %symbols)
{
   printf '%5d  ', $symbols{$i};

   my $replacement;
   if( $index < 52 )
   {
      $replacement = substr($dict, $index, 1);
   }
   else
   {
      my $d = $index - 52;
      $replacement = substr($dict, int($index / length($dict)), 1) .
                     substr($dict, $index % length($dict), 1);
   }

   print "$i -> $replacement\n";
   $index++;
}