added second solution for permutation step

Kyle Maune · Kyle Maune · commit c55545469e91 · 2014-07-15T17:09:23.000-07:00
diff --git a/Medium Difficulty/permutationStep2.js b/Medium Difficulty/permutationStep2.js
@@ -0,0 +1,36 @@
+// coderbyte solution for permutation step
+// splashinn
+
+function permutationStep(num) { 
+
+  var concat = function (arr) {
+    var s = '';
+    for (var i = 0; i < arr.length; i++) {
+      s += arr[i];
+    }
+
+    return s;
+  };
+
+  var equalPerm = function (a, b) {
+    a = (a + '').split('');
+    b = (b + '').split('');
+    a.sort();
+    b.sort();
+    return concat(a) == concat(b);
+  };
+
+  var f = (num + '').split('');
+  f.sort(function (a, b) { return a < b; });
+
+  if (concat(f) == num) {
+    return -1;
+  }
+
+  for (var i = num + 1; ; i++) {
+    if (equalPerm(num, i)) {
+      return i;
+    }
+  }
+  return equalPerm(123, 321);
+}
