1 files changed, 42 insertions, 0 deletions
diff --git a/day18/part1 b/day18/part1
new file mode 100755
index 0000000..70a0d94
--- /dev/null
+++ b/day18/part1
@@ -0,0 +1,42 @@
+#!/usr/bin/env ruby
+
+def valof(reg_file, reg_or_int)
+  if reg_or_int >= 'a' && reg_or_int <= 'z' then
+    return reg_file[reg_or_int] || 0
+  end
+  return reg_or_int.to_i
+end
+
+input = $stdin.readlines.map(&:chomp)
+
+reg = {}
+snd = 0
+pc = 0
+
+loop do
+  break if pc >= input.length
+  istr = input[pc].split
+  case istr[0]
+  when 'snd'
+    snd = valof(reg, istr[1])
+  when 'set'
+    reg[istr[1]] = valof(reg, istr[2])
+  when 'add'
+    reg[istr[1]] = valof(reg, istr[1]) + valof(reg, istr[2])
+  when 'mul'
+    reg[istr[1]] = valof(reg, istr[1]) * valof(reg, istr[2])
+  when 'mod'
+    reg[istr[1]] = valof(reg, istr[1]) % valof(reg, istr[2])
+  when 'rcv'
+    unless valof(reg, istr[1]) == 0 then
+      puts snd
+      break
+    end
+  when 'jgz'
+    if valof(reg, istr[1]) > 0 then
+      pc += valof(reg, istr[2])
+      pc -= 1
+    end
+  end
+  pc += 1
+end