AoC 2023, day 9

sub solve(@n --> List:D) {
    my @m = @n;
    my @N = @m.deepmap(*.clone),;

    while [email protected] > 1 {
        my @m_ = (^(+@m-1)).map({ @m[$_+1] - @m[$_] });
        @N.push(@m_.item);
        @m = @m_;
    }

    for +@N-2 ... 0 -> $i {
        @N[$i].push(   @N[$i].tail + @N[$i+1].tail);
        @N[$i].unshift(@N[$i].head - @N[$i+1].head);
    }

    @N[0].tail, @N[0].head
}

with [«+»] $*IN.lines.map({ solve(.words) }) {
    put 'part 1: ', .[0];
    put 'part 2: ', .[1];
}