3 files changed, 43 insertions(+), 0 deletions(-)

A day17/Makefile
A day17/day17.raku
A day17/input.txt

@@ 0,0 1,3 @@
+
+run:
+	raku day17.raku

@@ 0,0 1,39 @@
+my $match = slurp("input.txt")[0] ~~ m:Perl5/target area: x=(-?\d+)..(-?\d+), y=(-?\d+)..(-?\d+)/;
+my $ymin= $match[2];
+my $part1 = ($ymin * ($ymin + 1)) / 2;
+say "Part 1: $part1";
+
+my $xmin= $match[0];
+my $xmax = $match[1];
+my $ymax = $match[3];
+
+sub probe_lands_in_range($vel_x is copy, $vel_y is copy) {
+  my $pos_x = 0;
+  my $pos_y = 0;
+  while $pos_x < ($xmax + 1) &&
+    !($vel_x == 0 && $pos_x < $xmin) &&
+    !($pos_x > $xmin && $pos_y < $ymin) {
+      $pos_x += $vel_x;
+      $pos_y += $vel_y;
+      if $vel_x > 0 {
+        $vel_x -= 1;
+      }
+      $vel_y -= 1;
+      if $pos_x ~~ $xmin..$xmax && $pos_y ~~ $ymin..$ymax {
+        return True
+      }
+  }
+  return False
+}
+
+my $total_velocities = 0;
+
+for 1..($xmax * 2) -> $x {
+  for $ymin..$xmax -> $y {
+    if probe_lands_in_range($x, $y) {
+      $total_velocities++;
+    }
+  }
+}
+
+say "Part 2: $total_velocities";

@@ 0,0 1,1 @@
+target area: x=128..160, y=-142..-88