Day 05

1 files changed, 28 insertions, 0 deletions

diff --git a/day05/part1.rb b/day05/part1.rb
new file mode 100644
index 0000000..d582dce
--- /dev/null
+++ b/day05/part1.rb
@@ -0,0 +1,28 @@
+lines = $stdin.readlines
+
+brk = lines.index(?\n)
+stackin = lines[0..(brk-2)]
+movein = lines[(brk+1)..-1]
+
+numstacks = lines[brk-1].split[-1].to_i
+stacks = Array.new(numstacks) { [] }
+
+stackin.reverse.each do |rank|
+  stack = 0
+  until rank.empty? do
+    stacks[stack] << rank[1] if rank[0] == ?[
+    rank = rank[4..-1]
+    stack += 1
+  end
+end
+
+movein.each do |istr|
+  n, f, t = istr.scan(/\Amove (\d+) from (\d+) to (\d+)\Z/)[0].map(&:to_i)
+  f -= 1
+  t -= 1
+  n.times do
+    stacks[t].push(stacks[f].pop)
+  end
+end
+
+puts stacks.map(&:pop).join