#! perl -slw
use strict;
use List::Util qw[ reduce ]; $a = $b;

my @array = (1,4,5,6,7,9,10,23,34,44,55,56,57,59,70,80,90,100);
my $yardstick = '';
reduce {
    my $n = $a;
    $yardstick .= chr( $a ), $n++ while $n < $b;
    $b;
} @array;

print "$_ : ", ord( substr $yardstick, $_-1, 1 ) for map 10 * $_- 5, 1 .. 10;

__END__
c:\test>junk8
5 : 5
15 : 10
25 : 23
35 : 34
45 : 44
55 : 55
65 : 59
75 : 70
85 : 80
95 : 90