Add the first few solutions.

day2.cr

@@ -0,0 +1,27 @@
+lines = File.read("day2.txt").lines.map(&.split(",").map(&.to_i32)).flatten
+def run(lines, noun, verb)
+  lines[1] = noun
+  lines[2] = verb
+  pos = 0
+  loop do
+    case lines[pos]
+    when 1
+      lines[lines[pos+3]] = lines[lines[pos+1]] + lines[lines[pos+2]]
+      pos += 4
+    when 2
+      lines[lines[pos+3]] = lines[lines[pos+1]] * lines[lines[pos+2]]
+      pos += 4
+    when 99
+      break
+    end
+  end
+  lines[0]
+end
+100.times do |noun|
+  100.times do |verb|
+    if run(lines.dup, noun, verb) == 19690720
+      puts 100*noun + verb 
+      break
+    end
+  end
+end