fix| factorial solution now passes

Author: nik-rev

13_factorial/solution/factorial-solution.js

@@ -1,7 +1,7 @@
 const factorial = function(n) {
-  if (/[.-]/.match(n + '')) return;
-  if (n === 0 || n === 1) return 1;
-  return factorial(n - 1) + factorial(n - 2);
+  if (/[-.]/.test(n + '')) return;
+  if (+n === 0 || +n === 1) return 1;
+  return n * factorial(n - 1);
 };
 
 // Do not edit below this line