Add 2024/day2/part2.js

2024/day2/part2.js

@@ -0,0 +1,31 @@
+#!/usr/bin/env node
+
+var fs = require('fs');
+var data = fs.readFileSync(process.argv[2],'utf8').split('\n').filter(i=>i).map(i=>i.split(' ').map(i=>parseInt(i)));
+
+var safety_count = 0;
+
+function listwithout(list,idx) {
+ return list.slice(0,idx).concat(list.slice(idx+1));
+}
+
+function isreportsafe(report,retry=true) {
+ var first = report.slice(0,-1);
+ var diffs = first.map((elem,idx)=>report[idx+1]-elem);
+ if(diffs[0]<0) { //Is negative
+  diffs = diffs.map(i=>-i); //Negate it
+ }
+ for(var idx=0;idx<diffs.length;++idx) {
+  if(diffs[idx]<1 || diffs[idx]>3) {
+   //return false; //We need to test removal
+   //If an improvement is made then it will be by removing one of the elements associated with this diff
+   if(retry) return isreportsafe(listwithout(report,idx-1),false) || isreportsafe(listwithout(report,idx),false) || isreportsafe(listwithout(report,idx+1),false);
+   return false;
+  }
+ }
+ return true;
+}
+
+var safety_count = data.reduce((acc,report)=>acc+(isreportsafe(report)?1:0),0);
+
+console.log('Result:',safety_count);