foo.cc: In function 'int main()':
foo.cc:22:33: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
   22 |                         scanf("%d",&a[i][j]);
      |                                ~^  ~~~~~~~~
      |                                 |  |
      |                                 |  long long int*
      |                                 int*
      |                                %lld
In file included from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/istream:39,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/sstream:38,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/complex:45,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/ccomplex:39,
                 from stdc++.h:54:
In member function 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>]',
    inlined from 'int main()' at foo.cc:39:8:
/nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/ostream:202:25: warning: 'sum' may be used uninitialized [-Wmaybe-uninitialized]
  202 |       { return _M_insert(__n); }
      |                ~~~~~~~~~^~~~~
foo.cc: In function 'int main()':
foo.cc:35:13: note: 'sum' was declared here
   35 |         int sum;
      |             ^~~

[Hydro](https://hydro.ac)提供评测服务