Remove Nth Node From End of List

Remove Nth Node From End of List

the most important thing is that you must know the length of the  list;


l is length;



then remove is easy



And the complete code

class Solution {

public:

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

        int l = 0;

         ListNode* beg = new ListNode(0);     // you should create a new ListNode

         beg->next = head;

         ListNode* first = head;

        while(first)

        {

            l++;

            first = first->next;

              }

        

        l = l - n;

        first = beg;

        while(l>0)

        {  

            l--;

            first = first->next;

            }

        

        first->next = (first->next)->next;

        return beg->next;

    }

};