https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/
Given the head of a linked list, remove the nth node from the end of the list and return its head.
Example 1:
Input: head = [1,2,3,4,5], n = 2 Output: [1,2,3,5]
Example 2:
Input: head = [1], n = 1 Output: []
Example 3:
Input: head = [1,2], n = 1 Output: [1]
Solution:
class Solution {
public:
ListNode* removeNthFromEnd(ListNode* head, int n) {
ListNode *f = head;
ListNode *s = head;
for(int i=0; i<n; i++) {
f = f->next;
}
if (f==NULL) return head->next;
while(f->next != NULL) {
f= f->next;
s= s->next;
}
s->next = s->next->next;
return head;
}
};