day 3 with hopeful counting for part 2

day03/part1.lua

@@ -0,0 +1,24 @@
+local ZERO = string.byte("0", 1)
+local ONE = string.byte("1", 1)
+local total = 0
+local counts = {}
+for line in io.lines(arg[3]) do
+	for char = 1, #line do
+		if line:byte(char) == ONE then
+			counts[char] = (counts[char] or 0) + 1
+		end
+	end
+	total = total + 1
+end
+
+local gamma, epsilon = 0, 0
+for i, count in ipairs(counts) do
+	gamma, epsilon = gamma * 2, epsilon * 2
+	if count > total / 2 then
+		gamma = gamma + 1
+	else
+		epsilon = epsilon + 1
+	end
+end
+
+print(gamma * epsilon)

day03/part2.lua

@@ -0,0 +1,33 @@
+local ZERO = string.byte("0", 1)
+local ONE = string.byte("1", 1)
+local total = 0
+local counts = {}
+for line in io.lines(arg[3]) do
+	for char = 1, #line do
+		if line:byte(char) == ONE then
+			counts[char] = (counts[char] or 0) + 1
+		end
+	end
+	total = total + 1
+end
+
+local least, most, lmax, mmax = nil, nil, 0, 0
+for line in io.lines(arg[3]) do
+	local lcur, mcur, lin, min = 0, 0, true, true
+	for char = 1, #line do
+		if line:byte(char) == ONE then
+			if counts[char] >= total / 2 then
+				if min then mcur = mcur + 1 end
+			else
+				min = false
+			end
+		else
+			if counts[char] < total / 2 then
+				if min then mcur = mcur + 1 end
+			else
+				min = false
+			end
+		end
+	end
+	print(line, mcur)
+end