Added removeNthFromEnd solution

Author: nhistory

remove-nth-node-from-end-of-list/nhistory.js

@@ -0,0 +1,33 @@
+var removeNthFromEnd = function (head, n) {
+  // Edge case: If the list is empty
+  if (!head) return null;
+
+  // Create a dummy node that points to the head
+  let dummy = new ListNode(0);
+  dummy.next = head;
+  let length = 0,
+    curr = head;
+
+  // Calculate the length of the list
+  while (curr) {
+    length++;
+    curr = curr.next;
+  }
+
+  // Find the length-n node from the beginning
+  length = length - n;
+  curr = dummy;
+  while (length > 0) {
+    length--;
+    curr = curr.next;
+  }
+
+  // Skip the desired node
+  curr.next = curr.next.next;
+
+  // Return the head, which may be a new head if we removed the first node
+  return dummy.next;
+};
+
+// TC: O(n)
+// SC: O(1)