Add 2024/day1/part2.js

2024/day1/part2.js

@@ -0,0 +1,19 @@
+#!/usr/bin/env node
+
+const list1=[];
+const list2=[];
+
+require('fs').readFileSync('input.txt','utf8').split('\n').filter(i=>i).forEach(line=>{
+ const parts = line.split('   ').map(i=>parseInt(i));
+ list1.push(parts[0]);
+ list2.push(parts[1]);
+});
+
+const counts = require('lodash').countBy(list2);
+
+var absurdscore=0;
+for(let num of list1) {
+ absurdscore+=num*(counts[num]||0);
+}
+
+console.log('Result:',absurdscore);