Day 1 part 2

Author: timocp

gleam.toml

@@ -16,6 +16,7 @@ version = "1.0.0"
 gleam_stdlib = ">= 0.34.0 and < 2.0.0"
 argv = ">= 1.0.2 and < 2.0.0"
 simplifile = ">= 2.2.0 and < 3.0.0"
+tote = ">= 1.0.2 and < 2.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

@@ -7,10 +7,12 @@ packages = [
   { name = "gleam_stdlib", version = "0.51.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "14AFA8D3DDD7045203D422715DBB822D1725992A31DF35A08D97389014B74B68" },
   { name = "gleeunit", version = "1.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "F7A7228925D3EE7D0813C922E062BFD6D7E9310F0BEE585D3A42F3307E3CFD13" },
   { name = "simplifile", version = "2.2.0", build_tools = ["gleam"], requirements = ["filepath", "gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "0DFABEF7DC7A9E2FF4BB27B108034E60C81BEBFCB7AB816B9E7E18ED4503ACD8" },
+  { name = "tote", version = "1.0.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "tote", source = "hex", outer_checksum = "A249892E26A53C668897F8D47845B0007EEE07707A1A03437487F0CD5A452CA5" },
 ]
 
 [requirements]
 argv = { version = ">= 1.0.2 and < 2.0.0" }
 gleam_stdlib = { version = ">= 0.34.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.0.0 and < 2.0.0" }
 simplifile = { version = ">= 2.2.0 and < 3.0.0" }
+tote = { version = ">= 1.0.2 and < 2.0.0" }

src/adventofcode2024.gleam

@@ -13,6 +13,8 @@ fn run(n: Int) -> Nil {
   let input = read_input(n)
   io.print("Day " <> int.to_string(n) <> " Part 1: ")
   io.println(int.to_string(day1.part1(input)))
+  io.print("Day " <> int.to_string(n) <> " Part 2: ")
+  io.println(int.to_string(day1.part2(input)))
 }
 
 fn read_input(n: Int) -> String {

src/day1.gleam

@@ -2,12 +2,22 @@ import gleam/int
 import gleam/list
 import gleam/string
 
+import tote/bag
+
 pub fn part1(input: String) -> Int {
   let #(left, right) = parse_input(input)
   list.zip(left, right)
   |> list.fold(0, fn(acc, pair) { acc + int.absolute_value(pair.0 - pair.1) })
 }
 
+pub fn part2(input: String) -> Int {
+  let #(left, right) = parse_input(input)
+  let left_count = bag.from_list(left)
+  right
+  |> list.map(fn(r) { r * bag.copies(left_count, r) })
+  |> list.fold(0, fn(acc, r) { acc + r })
+}
+
 fn parse_input(input: String) -> #(List(Int), List(Int)) {
   let data =
     input

test/day1_test.gleam

@@ -18,3 +18,7 @@ const example1 = "3   4
 pub fn part1_test() {
   day1.part1(example1) |> should.equal(11)
 }
+
+pub fn part2_test() {
+  day1.part2(example1) |> should.equal(31)
+}