Added Leetcode solution in java to problem: Remove nth node from end in a linked list

Author: adenashameem

leetcode/java/linkedlist/19.java

@@ -0,0 +1,46 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
+class Solution {
+    public ListNode removeNthFromEnd(ListNode head, int n) {
+        ListNode dummy = new ListNode(0);
+        dummy.next = head;
+        ListNode first = dummy;
+        ListNode second = dummy;
+        
+        for (int i = 0; i < n; i++) { 
+  
+            // If count of nodes in the given 
+            // linked list is <= N 
+            if (second.next == null) { 
+  
+                // If count = N i.e. delete the head node 
+                if (i == n - 1) 
+                    first = first.next; 
+                
+            } 
+            second = second.next; 
+        } 
+  
+        // Increment both the pointers by one until 
+        // second pointer reaches the end 
+        while (second.next != null) { 
+            first = first.next; 
+            second = second.next; 
+        } 
+  
+        // First must be pointing to the 
+        // Nth node from the end by now 
+        // So, delete the node first is pointing to 
+        first.next = first.next.next; 
+        return dummy.next;
+    } 
+    
+}