Well, here is a quick hack comparing two hashing algorithms. The first keys on the sum of the digits (1234 -> 10), The second uses the last two chars (1234 -> 34). Since we started with a random set, the results aren't too surprising..... 
#!/usr/bin/perl -wT
use strict;

my $count = shift || 10000;
my $verbose = shift || 0;

my %hash;
for (1..$count) {
  my $value = int(rand(899_999_999)+100_000_000);
  
  # uncomment one of the next two lines to toggle algorithms
  #my $hv = digitsum($value);
  my $hv = lastchars($value);

  print "$value => $hv\n" if $verbose;
  $hash{$hv}++;
}

my $keycount = keys %hash;
my @orderedvalues = (sort {$a <=> $b} values %hash);
my ($min,$max) = (@orderedvalues)[0,-1];

print "$keycount keys\n";
print "Min:$min\n";
print "Max:$max\n";

for (@orderedvalues) {
  printf "%4d:",$_;
  print '*' x int($_/$max*70),"\n";
}

sub digitsum {
  my $key = shift;
  my $hv;
  $hv += $_ for (split//,$key);
  return $hv;
}

sub lastchars {
  my $key = shift;
  my ($hv) = ($key =~ /(..)$/);
  return $hv;
}
=OUTPUT using lastchars
100 keys
Min:77
Max:119
  77:*********************************************
  79:**********************************************
  80:***********************************************
  80:***********************************************
  81:***********************************************
  82:************************************************
  85:**************************************************
  86:**************************************************
  86:**************************************************
  86:**************************************************
  87:***************************************************
  87:***************************************************
  88:***************************************************
  88:***************************************************
  88:***************************************************
  88:***************************************************
  88:***************************************************
  88:***************************************************
  88:***************************************************
  89:****************************************************
  89:****************************************************
  89:****************************************************
  90:****************************************************
  90:****************************************************
  91:*****************************************************
  91:*****************************************************
  92:******************************************************
  93:******************************************************
  93:******************************************************
  93:******************************************************
  93:******************************************************
  94:*******************************************************
  94:*******************************************************
  95:*******************************************************
  95:*******************************************************
  95:*******************************************************
  96:********************************************************
  96:********************************************************
  97:*********************************************************
  97:*********************************************************
  97:*********************************************************
  97:*********************************************************
  98:*********************************************************
  98:*********************************************************
  98:*********************************************************
  99:**********************************************************
  99:**********************************************************
  99:**********************************************************
 100:**********************************************************
 100:**********************************************************
 100:**********************************************************
 100:**********************************************************
 101:***********************************************************
 102:************************************************************
 102:************************************************************
 102:************************************************************
 103:************************************************************
 103:************************************************************
 103:************************************************************
 104:*************************************************************
 105:*************************************************************
 105:*************************************************************
 106:**************************************************************
 106:**************************************************************
 106:**************************************************************
 106:**************************************************************
 106:**************************************************************
 106:**************************************************************
 107:**************************************************************
 107:**************************************************************
 107:**************************************************************
 107:**************************************************************
 108:***************************************************************
 109:****************************************************************
 109:****************************************************************
 109:****************************************************************
 109:****************************************************************
 109:****************************************************************
 110:****************************************************************
 110:****************************************************************
 110:****************************************************************
 110:****************************************************************
 111:*****************************************************************
 111:*****************************************************************
 112:*****************************************************************
 112:*****************************************************************
 113:*****************************************************************
+*
 113:*****************************************************************
+*
 114:*****************************************************************
+**
 114:*****************************************************************
+**
 114:*****************************************************************
+**
 115:*****************************************************************
+**
 116:*****************************************************************
+***
 116:*****************************************************************
+***
 116:*****************************************************************
+***
 116:*****************************************************************
+***
 116:*****************************************************************
+***
 118:*****************************************************************
+****
 118:*****************************************************************
+****
 119:*****************************************************************
+*****

=OUTPUT using digitsum
59 keys
Min:1
Max:477
   1:
   1:
   1:
   2:
   2:
   2:
   4:
   4:
   5:
   5:
   6:
  10:*
  12:*
  12:*
  16:**
  19:**
  21:***
  22:***
  25:***
  29:****
  35:*****
  45:******
  51:*******
  51:*******
  63:*********
  68:*********
  74:**********
  88:************
  96:**************
 113:****************
 127:******************
 138:********************
 145:*********************
 152:**********************
 172:*************************
 184:***************************
 209:******************************
 225:*********************************
 226:*********************************
 242:***********************************
 249:************************************
 266:***************************************
 283:*****************************************
 294:*******************************************
 309:*********************************************
 341:**************************************************
 364:*****************************************************
 380:*******************************************************
 381:*******************************************************
 383:********************************************************
 422:*************************************************************
 424:**************************************************************
 439:****************************************************************
 441:****************************************************************
 446:*****************************************************************
 458:*****************************************************************
+**
 464:*****************************************************************
+***
 476:*****************************************************************
+****
 477:*****************************************************************
+*****

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-Blake

In reply to Re5: brainteaser: splitting up a namespace evenly by blakem
in thread brainteaser: splitting up a namespace evenly by perrin

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