remove-nth-node-from-end-of-list.txt

/**
 * 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) {
		if (head == NULL || head->next == NULL) {
			return NULL;
		}
		ListNode *pLeft = head, *pRight = head;
		for (int i = 0; i < n; i ++) {
			pRight = pRight->next;
		}
		if (pRight == NULL) {
			head = head->next;
		} else {
			while (pRight->next != NULL) {
				pLeft = pLeft->next;
				pRight = pRight->next;
			}
			pLeft->next = pLeft->next->next;
		}
        return head;
    }
};