day 3

day2.ts

@@ -0,0 +1,38 @@
+import fs from "node:fs";
+
+const input = fs.readFileSync("inputs/day2").toString();
+
+const rows = input.split("\n").filter(Boolean);
+
+function safe_levels(_row: number[]) {
+    const row = [..._row];
+    while (row.length > 1) {
+        const diff = row[1] - row[0];
+        if (diff > 3 || diff < 1) return false;
+        row.shift();
+    }
+    return true;
+}
+
+function puzzle1() {
+    return rows.map((row) => row.split(/\s+/g).map(i => +i))
+    .filter(row => safe_levels(row) || safe_levels(row.toReversed())).length;
+}
+
+console.log("Puzzle 1", puzzle1());
+
+function dampen_lists(row: number[]) {
+    const rows: number[][] = new Array(row.length).fill(row).map((_row, i) => {
+        const row = [..._row];
+        row.splice(i, 1);
+        return row;
+    });
+    return [row, ...rows].filter(safe_levels).length > 0;
+}
+
+function puzzle2() {
+    return rows.map((row) => row.split(/\s+/g).map(i => +i))
+    .filter(row => dampen_lists(row) || dampen_lists(row.toReversed())).length;
+}
+
+console.log("Puzzle 2", puzzle2());

day3.ts

@@ -0,0 +1,40 @@
+import fs from "node:fs";
+
+const input = fs.readFileSync("inputs/day3").toString();
+
+
+function puzzle1() {
+    const mul_regex = /mul\(([0-9]{1,3}),([0-9]{1,3})\)/g;
+    let sum = 0;
+    let match: RegExpExecArray | null = null;
+    while ((match = mul_regex.exec(input)) !== null) {
+        sum += +match[1] * + +match[2];
+    }
+    return sum;
+}
+
+console.log("Puzzle 1", puzzle1());
+
+function puzzle2() {
+    const toggle_regex = /(?:do|don't)\(\)|mul\(([0-9]{1,3}),([0-9]{1,3})\)/g;
+    let enabled = true;
+    let sum = 0;
+    let match: RegExpExecArray | null = null;
+    while ((match = toggle_regex.exec(input)) !== null) {
+        switch (match[0]) {
+            case "do()":
+                enabled = true;
+                break;
+            case "don't()":
+                enabled = false;
+                break;
+            default:
+                if (!enabled) break;
+                sum += +match[1] * + +match[2];
+                break;
+        }
+    }
+    return sum;
+}
+
+console.log("Puzzle 2", puzzle2());