foo.cc: In function 'int main()':
foo.cc:9:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
    9 | freopen("socialnetwork.in","r",stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:10:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   10 | freopen("socialnetwork.out","w",stdout);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

正在同步测试数据，请稍后
[Hydro](https://hydro.ac)提供评测服务