say my $tokens = 12, " tokens remaining.\n";
loop {
my $player = trim prompt "How many tokens do you want to remove; 1, 2 or 3? : ";
say "Nice try. $tokens tokens remaining.\n" and
next unless $player eq any <1 2 3>;
$tokens -= 4;
say "Computer takes {4 - $player}.\n$tokens tokens remaining.\n";
say "Computer wins." and last if $tokens <= 0;
}
Output:
12 tokens remaining.
How many tokens do you want to remove; 1, 2 or 3? : 3
Computer takes 1.
8 tokens remaining.
How many tokens do you want to remove; 1, 2 or 3? : 6
Nice try. 8 tokens remaining.
How many tokens do you want to remove; 1, 2 or 3? : G
Nice try. 8 tokens remaining.
How many tokens do you want to remove; 1, 2 or 3? : 2
Computer takes 2.
4 tokens remaining.
How many tokens do you want to remove; 1, 2 or 3? : 1
Computer takes 3.
0 tokens remaining.
Computer wins.