feat: solve day 2 puzzle 1

src/day02/puzzle1.lua

@@ -0,0 +1,38 @@
+local utils = require "utils"
+local puzzle1 = {}
+
+function puzzle1.splitRange(range)
+    local parts = utils.split(range, "-")
+    return tonumber(parts[1]), tonumber(parts[2])
+end
+
+function puzzle1.isValid(id)
+    local str = tostring(id)
+    if #str % 2 == 1 then
+        return true
+    end
+    local mid = #str / 2
+    return str:sub(1, mid) ~= str:sub(mid + 1)
+end
+
+function puzzle1.countInvalids(range)
+    local min, max = puzzle1.splitRange(range)
+    local total = 0
+    for i=min, max do
+        if not puzzle1.isValid(i) then
+            total = total + i
+        end
+    end
+    return total
+end
+
+function puzzle1.solve(input)
+    local ranges = utils.split(input, ",")
+    local total = 0
+    for _, range in ipairs(ranges) do
+        total = total + puzzle1.countInvalids(range)
+    end
+    return total
+end
+
+return puzzle1

src/day02/puzzle2.lua

@@ -0,0 +1,7 @@
+local puzzle2 = {}
+
+function puzzle2.solve(input)
+    return 0
+end
+
+return puzzle2

src/lib/utils.lua

@@ -78,14 +78,18 @@ function utils.waitForKey(targetKey)
     end
 end
 
-function utils.splitLines(data)
+function utils.split(data, sep)
     local t = {}
-    for str in string.gmatch(data, "([^\n]+)") do
+    for str in string.gmatch(data, "([^" .. sep .. "]+)") do
         table.insert(t, str)
     end
     return t
 end
 
+function utils.splitLines(data)
+    return utils.split(data, "\n")
+end
+
 function utils.round(x)
     return x >= 0 and math.floor(x + 0.5) or math.ceil(x - 0.5)
 end