days 5-11

11/1.pl

@@ -0,0 +1,53 @@
+#!/usr/bin/perl
+
+use strict;
+use v5.10;
+use Data::Dumper;
+
+sub get_grid ($) {
+    my $serial = shift;
+
+    my @grid;
+    foreach my $y (1..300) {
+        my @x;
+        foreach my $x (1..300) {
+            my $pl = ((($x+10)*$y)+$serial)*($x+10);
+            $pl = (($pl / 100) % 10)-5;
+            push @x, $pl;
+
+        }
+        push @grid, \@x
+    }
+    return @grid;
+}
+
+#122,79, grid serial number 57: power level -5.
+#my @grid=get_grid(57);
+#say $grid[78][121];
+
+#217,196, grid serial number 39: power level  0.
+#@grid=get_grid(39);
+#say $grid[195][216];
+
+#101,153, grid serial number 71: power level  4.
+#@grid=get_grid(71);
+#say $grid[152][100];
+my $serial = $ARGV[0];
+my @grid = get_grid($serial);
+
+my $biglytotal = -9999;
+my $coords;
+for (my $y=2; $y < 299; $y++) {
+    for (my $x=2; $x < 299; $x++) {
+        my $total = $grid[$y-1][$x-1] + $grid[$y-1][$x] + $grid[$y-1][$x+1] + 
+                    $grid[$y][$x-1] + $grid[$y][$x] + $grid[$y][$x+1] + 
+                    $grid[$y+1][$x-1] + $grid[$y+1][$x] + $grid[$y+1][$x+1];
+        if ($total > $biglytotal) {
+            $biglytotal = $total;
+            $coords = "$x,$y";
+        }
+    }
+}
+say $coords;
+
+