solves remove nth node from end of linked list

Author: anishLearnsToCode

README.md

@@ -27,6 +27,7 @@
 |  16  | [3Sum Closest](https://leetcode.com/problems/3sum-closest)                                                                                                |                                                                 [![Java](assets/java.png)](src/ThreeSumClosest.java)                                                                 |                                                                                                                                   |
 |  17  | [Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number)                                              |                                                        [![Java](assets/java.png)](src/LetterCombinationsOfAPhoneNumber.java)                                                         |                                                                                                                                   |
 |  18  | [4Sum](https://leetcode.com/problems/4sum)                                                                                                                |                                                                     [![Java](assets/java.png)](src/FourSum.java)                                                                     |                                                                                                                                   |
+|  19  | [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list)                                                        |                                                           [![Java](assets/java.png)](src/RemoveNthNodeFromEndOfList.java)                                                            |                                                                                                                                   |
 |  20  | [ValidParentheses](https://leetcode.com/problems/valid-parentheses/)                                                                                      |                                  [![Java](assets/java.png)](src/ValidParentheses.java) [![Python](assets/python.png)](python/valid_parentheses.py)                                   |                                                                                                                                   |
 |  21  | [Merge 2 Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)                                                                             |                                [![Java](assets/java.png)](src/Merge2SortedLists.java) [![Python](assets/python.png)](python/merge_2_sorted_lists.py)                                 |                                                                                                                                   |
 |  26  | [Remove Duplicates From Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/)                                                 |                  [![Java](assets/java.png)](src/RemoveDuplicatesFromSortedArray.java) [![Python](assets/python.png)](python/remove_duplicates_from_sorted_array.py)                  |                                                                                                                                   |

src/RemoveNthNodeFromEndOfList.java

@@ -0,0 +1,32 @@
+
+public class RemoveNthNodeFromEndOfList {
+    public static class ListNode {
+        int val;
+        ListNode next;
+        ListNode() {}
+        ListNode(int val) { this.val = val; }
+        ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+    }
+
+    public ListNode removeNthFromEnd(ListNode head, int n) {
+        final int length = length(head);
+        final int removalIndex = length - n;
+        if (removalIndex == 0) return head.next;
+        ListNode current = head;
+        for (int i = 0 ; i < removalIndex - 1 ; i++) {
+            current = current.next;
+        }
+        current.next = current.next.next;
+        return head;
+    }
+
+    private int length(ListNode head) {
+        int count = 0;
+        ListNode current = head;
+        while (current != null) {
+            count++;
+            current = current.next;
+        }
+        return count;
+    }
+}