链表结构：
https://blog.csdn.net/sinat_35512245/article/details/54600187
https://cloud.tencent.com/developer/article/1339603
https://blog.csdn.net/u013696062/article/details/40787591
https://cloud.tencent.com/developer/article/1339603
http://www.codebelief.com/article/2016/11/linklist-implementation/
https://www.cnblogs.com/scandy-yuan/archive/2013/01/06/2847801.html
反转链表：
https://www.javazhiyin.com/32787.html
c++算法面试经验：
https://zhuanlan.zhihu.com/c_1089214591082233856
pat比赛？：
https://blog.csdn.net/zhaohaibo_/article/details/90339315
https://blog.csdn.net/zhaohaibo_/article/details/90340120