From 91994445fd466993fec00edca33ac18b2b3d9f20 Mon Sep 17 00:00:00 2001
From: Pedro Correa <pedro8correa@gmail.com>
Date: Mon, 8 Dec 2025 20:49:28 -0300
Subject: [PATCH] :sparkles: (Gleam) aoc day 3

---
 output.log             | 12 +++++++++++
 src/day_03.gleam       | 47 ++++++++++++++++++++++++++++++++++++++++++
 test/day_03_test.gleam | 29 ++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 output.log
 create mode 100644 src/day_03.gleam
 create mode 100644 test/day_03_test.gleam

diff --git a/output.log b/output.log
new file mode 100644
index 0000000..1d74af1
--- /dev/null
+++ b/output.log
@@ -0,0 +1,12 @@
+.......
+assert test/day_03_test.gleam:16
+ test: day_03_test.calculate_jolts_test
+ code: assert "987654321111111"
+    |> day_03.format_input
+    |> day_03.calculate_highest_jolts
+    == 357
+ left: 332690
+right: literal
+ info: Assertion failed.
+
+7 passed, 1 failures
diff --git a/src/day_03.gleam b/src/day_03.gleam
new file mode 100644
index 0000000..066ef12
--- /dev/null
+++ b/src/day_03.gleam
@@ -0,0 +1,47 @@
+import gleam/bool
+import gleam/int
+import gleam/list
+import gleam/string
+
+pub fn format_input(input: String) -> List(List(Int)) {
+  input
+  |> string.split("\n")
+  |> list.filter_map(fn(line) {
+    use <- bool.guard(when: line == "", return: Error(""))
+
+    line
+    |> string.split("")
+    |> list.map(fn(b) {
+      let assert Ok(b) = int.parse(b)
+      b
+    })
+    |> Ok
+  })
+}
+
+fn get_highest_numbers(bank: List(Int), acc: #(Int, Int)) -> #(Int, Int) {
+  case bank {
+    [] -> acc
+    [jolt] -> #(jolt, acc.0)
+    [jolt, ..rest] -> {
+      let #(prev_jolt, prev_acc) = get_highest_numbers(rest, acc)
+      let actual_acc = jolt * 10 + prev_jolt
+
+      case jolt > prev_jolt, actual_acc > prev_acc {
+        True, True -> #(jolt, actual_acc)
+        False, True -> #(prev_jolt, actual_acc)
+        True, False -> #(jolt, prev_acc)
+        False, False -> #(prev_jolt, prev_acc)
+      }
+    }
+  }
+}
+
+pub fn calculate_highest_jolts(banks: List(List(Int))) -> Int {
+  banks
+  |> list.map(fn(bank) {
+    let #(_, v) = get_highest_numbers(bank, #(0, 0))
+    v
+  })
+  |> list.fold(0, fn(acc, value) { acc + value })
+}
diff --git a/test/day_03_test.gleam b/test/day_03_test.gleam
new file mode 100644
index 0000000..cfc82f1
--- /dev/null
+++ b/test/day_03_test.gleam
@@ -0,0 +1,29 @@
+import day_03
+import simplifile
+
+pub fn read_input_test() {
+  assert "987654321111111\n811111111111119\n234234234234278\n818181911112111"
+    |> day_03.format_input
+    == [
+      [9, 8, 7, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 1, 1],
+      [8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9],
+      [2, 3, 4, 2, 3, 4, 2, 3, 4, 2, 3, 4, 2, 7, 8],
+      [8, 1, 8, 1, 8, 1, 9, 1, 1, 1, 1, 2, 1, 1, 1],
+    ]
+}
+
+pub fn calculate_jolts_test() {
+  assert "987654321111111\n811111111111119\n234234234234278\n818181911112111"
+    |> day_03.format_input
+    |> day_03.calculate_highest_jolts
+    == 357
+}
+
+pub fn calculate_jolts_for_real_test() {
+  let assert Ok(file) = simplifile.read("input/day_03")
+
+  assert file
+    |> day_03.format_input
+    |> day_03.calculate_highest_jolts
+    == 17_311
+}
-- 
2.51.2