sub strip-useless( $claim ) {
    # takes an Elven Claim and reduces it to an array:
    # [ x y x-offset y-offset ] where every element is Int

    my @stripped = $claim.split( " " );

    @stripped = @stripped[2..*];

    my @xy = @stripped[0].split( "," );

    my $y = @xy[1].comb.Array;

    $y.pop;

    @xy[1] = $y.join;

    my @offset = @stripped[1].split( "x" );

    @xy.append( @offset ).map: { .Int };

}

my $sampleid = "#183 @ 903,595: 21x25";

sub get-rect-coords( @rect ) {

    my ($x, $y, $x-offset, $y-offset) = @rect;

    $x-offset += $x;
    $y-offset += $y;

    for $y..^$y-offset -> $cur-y {
        for $x..^$x-offset -> $cur-x {

            take $cur-x ~ "x" ~ $cur-y;

        }
    }
}

sub toss-in-bag( %bag, @rect ) {
    my @coords = gather get-rect-coords( @rect );
    for @coords -> $c {
        %bag{ $c }++;
    }
    say "Tossed @rect[0]x@rect[1] in the bag."
}

sub process-claims( $filename ) {

    my @claims = $filename.IO.lines;
    my %cloth;

    for @claims -> $claim {

        toss-in-bag( %cloth, strip-useless( $claim ) );

    }

    %cloth;

}

my %bag = process-claims( "claims.txt" );

my $duplicate-claims-list = %bag.values.grep: none 1;

my $num-dups = $duplicate-claims-list.elems;

say "Located $num-dups duplicate claims using a HASH!";