#ifndef S0025_REVERSE_NODES_IN_K_GROUP
#define S0025_REVERSE_NODES_IN_K_GROUP

#include <utility>
#include <tuple>

using namespace std;

struct ListNode {
  int val;
  ListNode* next;
  ListNode() : val(0), next(nullptr) {}
  ListNode(int x) : val(x), next(nullptr) {}
  ListNode(int x, ListNode* next) : val(x), next(next) {}
};

class Solution {
 public:
  ListNode* reverseKGroup(ListNode* head, int k);
};

#endif