REVERSE NODES IN K-GROUP

	class Solution {
	public:
	    ListNode* reverseKGroup(ListNode* head, int k) {
	            int count = 0;
	        ListNode* current = head;
	        // Count the number of nodes in the list
	        while (current != nullptr && count < k) {
	            current = current->next;
	            count++;
	        }
	        // If there are at least k nodes, reverse the current group
	        if (count == k) {
	            ListNode* reversedGroup = reverseList(head, k);
	            // Recursively reverse the rest of the list
	            head->next = reverseKGroup(current, k);
	            return reversedGroup;
	        }
	        // If there are fewer than k nodes, return the original list
	        return head;
	    
	    }
	private:
	    // Helper function to reverse a group of k nodes
	    ListNode* reverseList(ListNode* head, int k) {
	        ListNode* prev = nullptr;
	        ListNode* current = head;
	        ListNode* next = nullptr;
	        // Reverse the k nodes
	        for (int i = 0; i < k; ++i) {
	            next = current->next;
	            current->next = prev;
	            prev = current;
	            current = next;
	        }
	        return prev;  // New head of the reversed group
	    }
};