20170728 - Remove Nth Node From End of List

/**
 * 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* l = new ListNode(0);
	l->next = head;
	ListNode* r = l;
	ListNode* result = l;

	for (int i = 0; i < n; i++)
	{
		r = r->next;
	}
	while (r->next != NULL)
	{
		l = l->next;
		r = r->next;
	}
	l->next = l->next->next;

	return result->next;
}
};