add solution 019[js]

Author: limbowandering

solution/019.Remove Nth Node From End of List/Solution.js

@@ -0,0 +1,13 @@
+const removeNthFromEnd = function(head, n){
+  let left, before, right = head;
+  left = before = {next: head};
+  while(n--){
+      right = right.next;
+  }
+  while(right){
+      right =right.next;
+      left = left.next;
+  }
+  left.next = left.next.next;
+  return before.next;
+}