LC19.cpp

/*
19. Remove Nth Node From End of List
Given the head of a linked list, remove the nth node from the end of the list and return its head.

Input: head = [1,2,3,4,5], n = 2
Output: [1,2,3,5]
*/

class Solution {
    public:

    Solution() {
        std::ios_base::sync_with_stdio(false);
        cin.tie(NULL);
    }

    ListNode* removeNthFromEnd(ListNode* head, int n) {

        ListNode* dummy = new ListNode(0);
        dummy->next = head;

        ListNode* first = dummy;
        ListNode* second = dummy;

        for (int = 0; i < n + 1; i++) {
            first = first->next;
        }

        while (first != nullptr) {
            first = first->next;
            second = second->next;
        }

        second->next = second->next->next;

        return dummy->next;
    }
};