In file included from /in/Compile/check.cpp:7:
/in/sokoban.hpp:13:17: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
    grid.resize(n);
         ~~~~~~ ^
/in/sokoban.hpp:15:26: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
        std::cin >> grid[i];
                    ~~~~ ^
/in/sokoban.hpp:25:45: error: unused parameter 'grid' [-Werror,-Wunused-parameter]
std::string solve(std::vector<std::string> &grid){
                                            ^
3 errors generated.
/in/Compile/Makefile:16: recipe for target 'main' failed
make: *** [main] Error 1