day 22 part 1

day22/part1.lua

@@ -0,0 +1,31 @@
+#!/usr/bin/env luajit
+require("utils")
+
+local ranges = {}
+for line in io.lines(arg[3]) do
+	local b, x0, x1, y0, y1, z0, z1 = line:match("(.*) x=(.*)%.%.(.*),y=(.*)%.%.(.*),z=(.*)%.%.(.*)")
+	if b == "on" then b = true else b = false end
+	table.insert(ranges, {
+		b=b,
+		x0=tonumber(x0),
+		x1=tonumber(x1),
+		y0=tonumber(y0),
+		y1=tonumber(y1),
+		z0=tonumber(z0),
+		z1=tonumber(z1)
+	})
+end
+
+local count = 0
+for x = -50, 50 do for y = -50, 50 do for z = -50, 50 do
+	local on = false
+	for _, r in pairs(ranges) do
+		if r.x0 <= x and x <= r.x1 and r.y0 <= y and y <= r.y1 and r.z0 <= z and z <= r.z1 then
+			on = r.b
+		end
+	end
+	if on then
+		count = count + 1
+	end
+end end end
+print(count)