反转链表

将链表里面的数字取出来，再倒着放回去就好了
/**

• Definition for singly-linked list.

• struct ListNode {

• int val;
  

• ListNode *next;
  

• ListNode(int x) : val(x), next(NULL) {}
  

• };
  /
  class Solution {
  public:
  ListNode reverseList(ListNode* head)
  {
  ListNode* tem=new ListNode(sizeof(ListNode));
  ListNode* t=tem;

   vector<int>cc;
   while(head!=NULL)
   {
       cc.push_back(head->val);
       head=head->next;
   }
  
   for(int i=cc.size()-1;i>=0;i--)
   {
       ListNode* ret=new ListNode(sizeof(ListNode));
       ret->val=cc[i];
       t->next=ret;
       t=t->next;
   }  
          t->next=NULL;
          return tem->next;
  

  }
  };

来源：CSDN

作者：qq_40742888

链接：https://blog.csdn.net/qq_40742888/article/details/104630120