19. Remove Nth Node From End of List.java

//best - beats 100 - O(n)

/**
 * 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;
        int total = 0;
        ListNode curr = head;
       
        while(curr!=null)
        {
            total +=1;
            curr = curr.next;
        }
        
        int remove = total-n;

        curr = dummy;

        for(int i=0;i<remove;i++)
        {
            curr = curr.next;
        }

        curr.next = curr.next.next;


        return dummy.next;
        
        
    }
}