first commit

day02/js/day02a.js

@@ -0,0 +1,45 @@
+import { promises as fsp } from "node:fs";
+
+async function asyncReadFile(filename) {
+    try {
+        const contents = await fsp.readFile(filename, "utf-8");
+
+        return contents.trim();
+    } catch (err) {
+        console.error(err);
+    }
+}
+
+/*
+const dataToParse =
+    "11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124";
+*/
+
+const dataToParse = await asyncReadFile("../input.txt");
+
+const isDuplicate = (val = "") => {
+    const strVal = `${val}`,
+        strLen = strVal.length;
+    if (!strLen || strLen % 2 === 1) return false;
+
+    return strVal.substring(0, strLen / 2) === strVal.substring(strLen / 2);
+};
+
+const ranges = dataToParse.split(",");
+let total = 0;
+
+ranges.forEach((range) => {
+    console.log(`> running range ${range}`);
+    const [start, end] = range.split("-"),
+        last = end * 1;
+    let curr = start * 1;
+    while (curr <= last) {
+        if (isDuplicate(curr)) {
+            total += curr;
+            console.log(`>> found duplicate: ${curr} / ${total}`);
+        }
+        curr++;
+    }
+});
+
+console.log(`> FINAL: ${total}`);