impl day 2 + simplification, woops implemented the wrong pattern checker

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
 .session
+.sessioncookie
 .tool_versions
 input

load-todays-input.bash

@@ -1,5 +1,6 @@
 day=$(date +%-e)
 day_zero=$(date +%0e)
+year=$(date +%Y)
 session=$(cat .sessioncookie)
 mkdir -p input
-curl -b "session=${session}" -o "./input/${day_zero}.txt" "https://adventofcode.com/2024/day/${day}/input"
+curl -b "session=${session}" -o "./input/${day_zero}.txt" "https://adventofcode.com/${year}/day/${day}/input"

main.ts

@@ -13,7 +13,9 @@ const solvables: Solvable[] = [];
 
   // only solve the latest day
   console.log("Solving latest day only:")
-  const day = solvables.toReversed()[0];
+  const day = solvables[0];
+  console.log(day)
+
   day.part1()
   day.part2()
 })()

solutions/02.ts

@@ -3,20 +3,56 @@ import { solvables } from "../main.ts";
 import type { Solvable } from "../solvable.ts";
 import { readInput } from "../utils.ts";
 
-class DayOne implements Solvable {
-    input = readInput('01')
 
-    public part1(): DayOne {
-        const vals: [string, number][] = this.input
-            .split("\n")
-            .map(line => [line[0], Number.parseInt(line.slice(1))]);
+// check if pattern with given width repeats in input
+const checkWindow = (width: number, input: number): boolean => {
+    const str = String(input);
+    for (let patternStart = 0; patternStart + 2 * width < str.length; patternStart += width) {
+        const leftPatIdx = [patternStart, patternStart + width]
+        const rightPatIdx = [patternStart + width, patternStart + width + width]
+        const patternRepeated = str.slice(...leftPatIdx) === str.slice(...rightPatIdx);
+        if (patternRepeated) {
+            return true;
+        }
+    }
+    return false
+}
+
+class DayTwo implements Solvable {
+    input = readInput('02')
+
+    public part1(): DayTwo {
+        const vals: [number, number][] = this.input
+            .split(",")
+            .map(range => range.split("-")
+                .map(Number) as [number, number]);
+
+        const invalid: number[] = [];
+        
+        for (const [start, end] of vals) {
+            for (let i = start; i <= end; i++) {
+                // if the number is of odd length, it can't have a repeating pattern
+                if (String(i).length % 2 !== 0) {
+                    continue;
+                }
+                // check for patterns with increasing width but never exceeding half the length of the number
+                for (let width = 2; width <= String(i).length / 2; width++) {
+                    if (checkWindow(width, i)) {
+                        invalid.push(i);
+                        break;
+                    }
+                }
+            }
+        }
+
+        console.log(invalid.reduce((a, b) => a + b, 0))
 
         return this
     }
 
-    public part2(): DayOne {
+    public part2(): DayTwo {
         return this
     }
 }
 
-solvables.push(new DayOne())
+solvables.push(new DayTwo())