I'm looking for a faster way to determine if all the digits in a 10 character string are unique.

Running this once is fast enough, but my program does this thousands of times. Each time the string is different, of course.

One slow way:

#!/usr/bin/perl -w
use strict;
while ( <> ) {
    chomp;
    die unless /^\d{10}$/;
    &uniq ( $_ ) == 1 ? print "1\n" : print "0\n";
}

sub uniq {
    for ( 0 .. 9 ) {
        return 0 if $_[0] !~ /$_/;
    }
    return 1;
}

[download]

Another slow way:

#!/usr/bin/perl -w
use strict;
while ( <> ) {
    chomp;
    die unless /^\d{10}$/;
    &uniq ( $_ ) == 1 ? print "1\n" : print "0\n";
}

sub uniq {
    my $x = $_[0];
    my @x = sort split //, $x;
    $x = join "", @x;
    $x =~ tr/0-9//s;
    length $x == 10 ? return 1 : return 0;
}

[download]

Thanks!

In reply to Determining uniqueness in a string. by Yzzyx

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