Add solution to day 8, in ruby.

2017/README.md

@@ -23,7 +23,7 @@ The current plan, in no particular order:
 - [ ] PHP
 - [ ] Prolog
 - [ ] Python
-- [ ] Ruby
+- [x] Ruby - [Day 08](./day-08/solution.rb)
 - [ ] Rust
 - [ ] Scala
 - [ ] Scheme

2017/day-08/solution.rb

@@ -0,0 +1,52 @@
+#!/usr/bin/env ruby
+
+
+$registers = Hash.new(0)
+
+def check_oper(a, oper, b)
+	a = $registers[a]
+	b = b.to_i
+
+	case oper
+	when ">"
+		return a > b
+	when "<"
+		return a < b
+	when ">="
+		return a >= b
+	when "<="
+		return a <= b
+	when "!="
+		return a != b
+	when "=="
+		return a == b
+	end
+	print oper
+end
+
+def do_oper(register, oper, val)
+	if oper == "inc"
+		$registers[register] += val.to_i
+	else
+		$registers[register] -= val.to_i
+	end
+end
+
+def cur_max
+	return $registers.max_by {|k,v| v}[1]
+end
+
+overall_max = 0
+
+while line = gets
+	parts = line.chomp.split " "
+
+	if check_oper parts[4], parts[5], parts[6]
+		do_oper parts[0], parts[1], parts[2]
+		overall_max = [overall_max, cur_max].max
+	end
+
+end
+
+print cur_max, "\n"
+print overall_max, "\n"