Compilare: main.cpp: In function 'int main()': main.cpp:67:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int i = 0; i < ans.size(); i++, std::cout << '\n') | ~~^~~~~~~~~~~~ main.cpp:68:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | for(int j = 0; j < ans[i].size(); ++j) | ~~^~~~~~~~~~~~~~~