Compilare: main.cpp: In function 'void print_sol(const std::vector<std::vector<int> >&, std::ofstream&)': main.cpp:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 10 | for (int i = 0; i < sol.size(); ++i) { | ~~^~~~~~~~~~~~ main.cpp:11:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 11 | for (int j = 0; j < sol[0].size(); ++j) { | ~~^~~~~~~~~~~~~~~