You have a point, though if I were going the verbose route, I would use the transliterate function rather than an index-substr. The back reference method come out slightly faster on my computer than index-substr with transliterate sightly ahead of both. It is moot however, tye's solution above (u5) pretty much spanks all of them.


use Benchmark qw( cmpthese ) ;

my $digits = 2491306578;

cmpthese( -5, {
  u1 => sub{
         for ( 0 .. 9 ) { return 0 if $digits !~ /$_/;} return 1;
           },

  u2 => sub{
          my @x = sort split //, $digits;
          my $x = join "", @x;
          $x =~ tr/0-9//s;
          length $x == 10 ? return 1 : return 0;
            },

  u3 => sub {
          return 0 if $digits =~ /(\d).*\1/; return 1;
            },

  u4 => sub {
          return $digits !~ /(.).*\1/;
            },

  u5 => sub {
          return $digits =~ /^(?=.*?0)(?=.*?1)(?=.*?2)(?=.*?3)(?=.*?4)
+(?=.*?5)(?=.*?6)(?=.*?7)(?=.*?8)(?=.*?9)/;
            },

  u6 => sub {
          return 0 unless $digits =~ y/0/0/;
          return 0 unless $digits =~ y/1/1/;
          return 0 unless $digits =~ y/2/2/;
          return 0 unless $digits =~ y/3/3/;
          return 0 unless $digits =~ y/4/4/;
          return 0 unless $digits =~ y/5/5/;
          return 0 unless $digits =~ y/6/6/;
          return 0 unless $digits =~ y/7/7/;
          return 0 unless $digits =~ y/8/8/;
          return 0 unless $digits =~ y/9/9/;
          return 1;
            },


  u9 => sub {
          return 0 if index($digits, substr($digits,0,1), 1) != -1;
          return 0 if index($digits, substr($digits,1,1), 2) != -1;
          return 0 if index($digits, substr($digits,2,1), 3) != -1;
          return 0 if index($digits, substr($digits,3,1), 4) != -1;
          return 0 if index($digits, substr($digits,4,1), 5) != -1;
          return 0 if index($digits, substr($digits,5,1), 6) != -1;
          return 0 if index($digits, substr($digits,6,1), 7) != -1;
          return 0 if index($digits, substr($digits,7,1), 8) != -1;
          return 0 if index($digits, substr($digits,8,1), 9) != -1;
          return 1;
            },

} );
__END__

[download]
       Rate    u1    u2    u9    u4    u3    u6    u5
u1  10982/s    --  -72%  -95%  -95%  -95%  -96%  -97%
u2  39808/s  262%    --  -83%  -83%  -83%  -85%  -90%
u9 229374/s 1989%  476%    --   -4%   -4%  -12%  -42%
u4 238244/s 2069%  498%    4%    --   -1%   -9%  -40%
u3 240061/s 2086%  503%    5%    1%    --   -8%  -39%
u6 261581/s 2282%  557%   14%   10%    9%    --  -34%
u5 394564/s 3493%  891%   72%   66%   64%   51%    --

[download]

In reply to Re^2: Determining uniqueness in a string. by thundergnat
in thread Determining uniqueness in a string. by Yzzyx

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