/in/foo.cc: In function 'int main()':
/in/foo.cc:58:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |         if (stone_idx < compressed_stones.size() && i == compressed_stones[stone_idx]) {
      |             ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~