Add 2024/day4/part2.js

2024/day4/part2.js

@@ -0,0 +1,16 @@
+#!/usr/bin/env node
+
+
+var input = require('fs').readFileSync(process.argv[2]||'input.txt','utf8').split('\n').filter(i=>i);
+
+var width = input.length;
+
+var sum=0;
+for(var i=1;i<width-1;++i) {
+ for(var j=1;j<width-1;++j) {
+  var isXMAS = input[i][j]=='A' && ((input[i-1][j-1]=='M'&&input[i+1][j+1]=='S') || (input[i-1][j-1]=='S'&&input[i+1][j+1]=='M')) && ((input[i-1][j+1]=='M'&&input[i+1][j-1]=='S') || (input[i-1][j+1]=='S'&&input[i+1][j-1]=='M'))
+  if(isXMAS) ++sum;
+ }
+}
+
+console.log('Result:',sum);