coins.cpp: In function 'std::vector<int> coin_flips(std::vector<int>, int)':
coins.cpp:8:12: error: 'vector' was not declared in this scope
    8 |     return vector<int>(1, sus ^ c);
      |            ^~~~~~~~~~~
coins.cpp:8:12: note: suggested alternatives:
In file included from /usr/include/c++/13/vector:66,
                 from coins.h:1,
                 from coins.cpp:1:
/usr/include/c++/13/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/13/vector:86:13: note:   'std::pmr::vector'
   86 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
grader.cpp: In function 'void shuffle(std::vector<int>&)':
grader.cpp:88:23: warning: 'void std::random_shuffle(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator<int*, vector<int> >]' is deprecated: use 'std::shuffle' instead [-Wdeprecated-declarations]
   88 |         random_shuffle(v.begin(), v.end());
      |         ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/13/algorithm:61,
                 from grader.cpp:5:
/usr/include/c++/13/bits/stl_algo.h:4581:5: note: declared here
 4581 |     random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
      |     ^~~~~~~~~~~~~~