text: //
  //  ConstantDefine.hpp
  //  towSum
  //
  //  Created by Xpeng on 2022/3/10.
  //
  
  #ifndef ConstantDefine_hpp
  #define ConstantDefine_hpp
  
  #include <stdio.h>
  
  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) {}
  };
  
  #endif /* ConstantDefine_hpp */
  