char *p = "ABCD",strcat
https://zhidao.baidu.com/question/1670289637897433867.html
https://wenku.baidu.com/view/fc35b5f3a48da0116c175f0e7cd184254b351b12.html
https://wenku.baidu.com/view/5b3f26ed9ec3d5bbfd0a7463.html
https://www.docin.com/p-1680287260.html
https://www.cnblogs.com/hpuwangjunling/p/4435026.html
C++一些简单题目总结: