foo.cc:30:1: error: extended character 《 is not valid in an identifier
   30 | 《面向对象的程序设计方法》课程赛事
      | ^
foo.cc:30:1: error: extended character 》 is not valid in an identifier
foo.cc:45:1: error: extended character © is not valid in an identifier
   45 | © 2005 - 2023 Vijos.org uibuild-2f1065f 沪ICP备14040537号-1
      | ^
foo.cc:1:1: error: expected unqualified-id before '/' token
    1 | / ZMS的养猪场🐖 / 题库 / OO11-5 list中Joseph问题 /
      | ^

[Hydro](https://hydro.ac)提供评测服务