Add solution #19

Author: JoshCrozier

README.md

@@ -21,6 +21,7 @@
 13|[Roman to Integer](./0013-roman-to-integer.js)|Easy|
 14|[Longest Common Prefix](./0014-longest-common-prefix.js)|Easy|
 17|[Letter Combinations of a Phone Number](./0017-letter-combinations-of-a-phone-number.js)|Medium|
+19|[Remove Nth Node From End of List](./0019-remove-nth-node-from-end-of-list.js)|Medium|
 20|[Valid Parentheses](./0020-valid-parentheses.js)|Easy|
 21|[Merge Two Sorted Lists](./0021-merge-two-sorted-lists.js)|Easy|
 27|[Remove Element](./0027-remove-element.js)|Easy|

solutions/0019-remove-nth-node-from-end-of-list.js

@@ -0,0 +1,40 @@
+/**
+ * 19. Remove Nth Node From End of List
+ * https://leetcode.com/problems/remove-nth-node-from-end-of-list/
+ * Difficulty: Medium
+ *
+ * Given the head of a linked list, remove the nth node from the end of the list
+ * and return its head.
+ */
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @param {number} n
+ * @return {ListNode}
+ */
+var removeNthFromEnd = function(head, n) {
+  const result = new ListNode();
+  let slow = result;
+  let fast = result;
+  slow.next = head;
+
+  for (let i = 0; i <= n; i++) {
+    fast = fast.next;
+  }
+
+  while (fast) {
+    fast = fast.next;
+    slow = slow.next;
+  }
+
+  slow.next = slow.next.next;
+
+  return result.next;
+};