use strict;
use warnings;

use Time::HiRes;

my $startTime = [Time::HiRes::gettimeofday ()];

my $str = '';
$str .= int rand 10 for 1..60000;

my @subs = sort map substr($str, $_, 400), 0..length($str)-1;

# Find the longest common prefix between any two neighbors
my $length = 0;
my $value = '';
for my $i (0..$#subs-1) {
  my ($common) = map length, ($subs[$i] ^ $subs[$i+1]) =~ /^(\0*)/;
  if ($common > $length) {
    ($length, $value) = ($common, substr($subs[$i], 0, $common));
  }
}

print "$value is the longest repeated substr\n";


print "Completed in " . Time::HiRes::tv_interval ($startTime) . "\n";