15-04-2024

class Solution {
public:
    ListNode* middleNode(ListNode* head) {
        ListNode* slow = head;
        ListNode* fast = head;
        while(fast != NULL && fast->next != NULL){
            slow = slow->next;
            fast = fast->next->next;
        }
        return slow;
    }
};


class Solution {
public:
    void reverse(ListNode* head, ListNode*& last){
        if(head == NULL){
            return ;
        }
        reverse(head->next, last);
        if(head and !head->next){
            last = head;
        }
        else{
            head->next->next = head;
        }
        
    }
    ListNode* reverseList(ListNode* head) {
       ListNode* cur = head;
        ListNode* lastNode = head;
        reverse(head, lastNode);
        if(head){
            head->next = NULL;
        }
        head = lastNode;
        return head;
    }
};