Solution for day 1 and 2 (2021)

Author: joshthompson

2021/01/index.js

@@ -0,0 +1,29 @@
+const fs = require('fs')
+
+fs.readFile(`${__dirname}/input.txt`, (_e, data) => {
+	const readings = data.toString().split('\n').map(Number)
+	console.log('Part 1', part1(readings))
+	console.log('Part 2', part2(readings))
+})
+
+function part1(readings) {
+  let increases = 0;
+  for (let i = 1; i < readings.length; i++) {
+    if (readings[i] > readings[i - 1]) {
+      increases++
+    }
+  }
+  return increases
+}
+
+function part2(readings) {
+  let increases = 0;
+  for (let i = 3; i < readings.length; i++) {
+    const prev = readings[i - 3] + readings[i - 2] + readings[i - 1];
+    const curr = readings[i - 2] + readings[i - 1] + readings[i];
+    if (curr > prev) {
+      increases++
+    }
+  }
+  return increases
+}