19/02/20 00:55:56.83 SyQ4jkRO.net
>>255 Perl5
$R = 0.0;
@s = map{($_) x (9-$_)} 1..8; #say "@s";
$t = @s; #say $t;
for (qw{11 13 17 23 31 37 41 43 47 53 61 67 71 73 83}) {
@o = split'';
my %h;
$h{$_}++ for @s;
my $r = $h{$o[0]}-- / $t;
$r *= $h{$o[1]}-- / ($t - 1);
$R += $r;
}
printf "%3.2f\n", $R;
実行結果
~ $ perl 13_255.pl
0.31