1 files changed, 46 insertions, 0 deletions
diff --git a/10/2.lua b/10/2.lua
new file mode 100644
index 0000000..377870d
--- /dev/null
+++ b/10/2.lua
@@ -0,0 +1,46 @@
+require "ext"
+
+local w, h = 40, 6
+local cpu = {
+	r = {x = 1},
+	isa = {
+		addx = {
+			nargs = 1,
+			cycles = 2,
+			f = function(self,v)
+				self.r.x = self.r.x + tonumber(v)
+			end
+		},
+		noop = {
+			nargs = 0,
+			cycles = 1,
+			f = function(self) end
+		}
+	}
+}
+
+local strength_sum = 0
+local cycle = 1
+for line in io.lines() do
+	local parts = {}
+	for part in line:gmatch("(%S+)") do
+		table.insert(parts,part)
+	end
+	local insn = table.remove(parts,1)
+	local ins = cpu.isa[insn]
+	assertf(ins, "No instruction %s in %s",insn,line)
+	for i = cycle,cycle + ins.cycles - 1 do
+		local crtpos = (i-1) % w
+		if crtpos + 1 == cpu.r.x or crtpos == cpu.r.x or crtpos - 1 == cpu.r.x then
+			io.write("#")
+		else
+			io.write(" ")
+		end
+		if i % 40 == 0 then
+			io.write("\n")
+		end
+	end
+	cycle = cycle + ins.cycles
+	ins.f(cpu,table.unpack(parts))
+end
+print(strength_sum)