Day 3

2024/03/index.ts

@@ -0,0 +1,29 @@
+const fs = require('fs');
+
+let input = fs.readFileSync(__dirname + '/input.txt', 'utf8');
+
+let result = 0;
+
+const expressions: Array<RegExpMatchArray> = Array.from(input.matchAll(/(do(n't)?)\(\)|mul\((\d{1,3}),(\d{1,3})\)/g));
+
+let enabled = true;
+
+expressions.forEach((match) => {
+    const expr = match[0];
+
+    // Part 2
+    if (expr.startsWith('do(')) {
+        enabled = true;
+        return;
+    }
+    if (expr.startsWith('don\'t(')) {
+        enabled = false;
+        return
+    }
+    // End part 2
+    if (enabled) {
+        result += (parseInt(match[3]) * parseInt(match[4]));
+    }
+});
+
+console.log(result);