/in/foo.cc: In function 'int main()':
/in/foo.cc:79:24: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare]
   79 |     for (int i = st; i <= ed; i++)
      |                      ~~^~~~~
/in/foo.cc:107:86: warning: comparison of integer expressions of different signedness: 'std::size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  107 |                 if (boat1[0] == 0 && flag[j] && boat1[0] != boat2[0] && tmp2.count() <= m)
      |                                                                         ~~~~~~~~~~~~~^~~~