days 5-11

9/1.pl

@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+use strict;
+use v5.10;
+use Data::Dumper;
+
+my $players = $ARGV[0];
+my $score = $ARGV[1];
+say "players: $players, score: $score";
+
+my $marble = 0;
+my $currentplayer = 0;
+my $currentpos = 0;
+my @board;
+my %score;
+
+# the splice approach isn't efficient, but it's fine for part 1.
+# it takes a couple of hours to solve part 2, but I was short of time to rewrite...
+
+while ($marble <= $score) {
+    if ($marble > 0 && ($marble % 23 == 0)) {
+        $score{$currentplayer} += $marble;
+        $currentpos = $currentpos - 8;
+        if ($currentpos < 0) {
+            $currentpos += (scalar @board);
+        }
+        #say "KEEP $currentplayer $marble ", $board[$currentpos];
+        $score{$currentplayer} += $board[$currentpos];
+        splice(@board,$currentpos,1);
+        $currentpos = ($currentpos+1) % (scalar @board);
+    } else {
+        splice(@board, $currentpos+1, 0, $marble);
+        
+        $currentpos = ($currentpos+2) % (scalar @board);
+    }
+    $marble++;
+    
+    
+    #say "player: $currentplayer, pos: $currentpos, board: ", join ",", @board;
+
+
+    $currentplayer = ($currentplayer + 1) % $players;
+}
+say Dumper \%score;
+my @keys = sort { $score{$b} <=> $score{$a} } keys %score;
+say $score{$keys[0]};