bunnyadad/remove-nth-node-from-end-of-list.cpp

## remove-nth-node-from-end-of-list.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* removeNthFromEnd(ListNode* head, int n)
    {
      ListNode dummy(0);
      dummy.next = head;
      ListNode *fast = &dummy;
      ListNode *slow = &dummy;
      while (n >= 0)
      {
        fast = fast->next;
        --n;
      }

      while (fast)
      {
        fast = fast->next;
        slow = slow->next;
      }

      slow->next = slow->next->next;
      return dummy.next;
    }
};