add day 3 solution

src/content/communitySolutions/03/dalurness.md

@@ -0,0 +1,112 @@
+---
+descriptions: ["gleam"]
+---
+
+### 2024 Solution Gleam
+
+#### Output
+
+```
+17
+Adds: 355, Removes: 174
+```
+
+```gleam
+import gleam/dict
+import gleam/int
+import gleam/io
+import gleam/list
+import gleam/option
+import gleam/pair
+import gleam/string
+import simplifile
+
+pub fn main() {
+  let increment = fn(x) {
+    case x {
+      option.Some(i) -> i + 1
+      option.None -> 1
+    }
+  }
+  let decrement = fn(x) {
+    case x {
+      option.Some(i) -> i - 1
+      option.None -> 0
+    }
+  }
+
+  let assembly_codes =
+    case simplifile.read("assembly_codes.txt") {
+      Ok(file_contents) -> file_contents
+      Error(_) -> {
+        io.println("failed to read file")
+        panic as "failed to read file"
+      }
+    }
+    |> string.split("\n")
+
+  assembly_codes
+  |> list.fold(0, fn(good_count, instr_set) {
+    let split_set = string.split(instr_set, "C")
+    case split_set {
+      [a_r, "P"] -> {
+        let instr_list = string.split(a_r, "")
+        let res =
+          list.fold(instr_list, #(True, dict.new()), fn(acc, instr) {
+            case instr {
+              "A" -> #(True, dict.upsert(pair.second(acc), "A", increment))
+              "R" -> {
+                case dict.get(pair.second(acc), "A") {
+                  Error(_) -> #(False, pair.second(acc))
+                  Ok(v) -> {
+                    case v == 0 {
+                      True -> #(False, pair.second(acc))
+                      False -> #(
+                        True,
+                        dict.upsert(pair.second(acc), "A", decrement),
+                      )
+                    }
+                  }
+                }
+              }
+              _ -> #(False, pair.second(acc))
+            }
+          })
+        case pair.first(res) {
+          True -> good_count + 1
+          False -> good_count
+        }
+      }
+      _ -> good_count
+    }
+  })
+  |> io.debug
+
+  let counts =
+    assembly_codes
+    // trim off last two letters
+    |> list.map(fn(code: String) { string.drop_end(code, 2) })
+    |> list.fold(#(0, 0), fn(acc, c) {
+      let code_count =
+        string.split(c, "")
+        |> list.fold(#(0, 0), fn(acc2, l) {
+          case l {
+            "A" | "C" -> #(pair.first(acc2) + 1, pair.second(acc2))
+            "R" | "P" -> #(pair.first(acc2), pair.second(acc2) + 1)
+            _ -> panic as "this shouldn't happen"
+          }
+        })
+      #(
+        pair.first(acc) + pair.first(code_count),
+        pair.second(acc) + pair.second(code_count),
+      )
+    })
+
+  io.println(
+    "Adds: "
+    <> int.to_string(pair.first(counts))
+    <> ", Removes: "
+    <> int.to_string(pair.second(counts)),
+  )
+}
+```