foo.cc: In function 'int main()':
foo.cc:33:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |     scanf ( "%d", &n );
      |     ~~~~~~^~~~~~~~~~~~
foo.cc:35:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         scanf ( "%d", &p[i] );
      |         ~~~~~~^~~~~~~~~~~~~~~
foo.cc:37:46: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   37 |     } for ( int i = 1 ; i <= n ; i++ ) scanf ( "%d", &c[i] );
      |                                        ~~~~~~^~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务