AOC Day 1

_posts/adam/advent-of-code/2022/2023-12-01-aoc.md

@@ -0,0 +1,80 @@
+---
+layout: post
+title:  Advent of Code 2023 Day 1 - Trebuchet?! - Solution in JavaScript
+author: adam
+permalink: /adam/2022-12-01-advent-of-code
+description: Solution for Advent of Code (AoC) Day 1 in JavaScript (JS)
+image: assets/img/advent-of-code-2023-day-1-trebuchet?!-in-javascript
+tags: dev js
+---
+
+I only made it through 3 days of posting solutions last year...let's see how this year goes.
+
+I got wrecked by part two because I started with a regex solution that failed to pick up a match when the last text digit was part of another one.  For example: "1eightwo".  My first version picked up 18, but because the "t" was part of "eight" it never picked up "two".  
+
+```js
+import fs from "fs";
+import { log } from "console";
+
+const lines = fs.readFileSync("./day1.txt", {encoding: "utf-8"}).split("\n");
+
+function isDigit(char) {
+  return /^\d$/.test(char);
+}
+
+function part1() {  
+  let sum = 0;
+
+  for (const line of lines) {
+    let firstNum, lastNum;
+    for (const c of line) {
+      if (isDigit(c)) {
+        if (!firstNum) {
+          firstNum = c;
+        }
+        lastNum = c;
+      }
+    }
+
+    const twoDigit = `${firstNum}${lastNum}`;
+    sum += Number(twoDigit);
+  }
+
+  log(sum);
+}
+
+function part2() {
+  let sum = 0;
+
+  for(const line of lines) {
+    let digits = [];
+
+    for (let i = 0; i < line.length; i++) {
+      const c = line[i];
+
+      if (isDigit(c)) {
+        digits.push(c);
+      }
+
+      const textDigits = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];
+      const lineSubstring = line.substring(i);
+      for (let d = 0; d < textDigits.length; d++) {
+        const textDigit = textDigits[d];
+        if (lineSubstring.startsWith(textDigit)) {
+          digits.push(d+1);
+        }
+      }
+    }
+
+    const lastIndex = digits.length - 1;
+    const twoDigits = `${digits[0]}${digits[lastIndex]}`;
+
+    sum += Number(twoDigits);
+  }
+
+  log(sum);
+}
+
+part1();
+part2();
+```

tools/previews/createPreview.mjs

@@ -38,5 +38,5 @@ if (title) {
     .toLowerCase()
     .replace(/\s+/g, "-")
     .replace(/\n/g, "-");
-  fs.writeFileSync(`${formattedTitle}.png`, png);
+  fs.writeFileSync(`../../assets/img/${formattedTitle}.png`, png);
 }