Compilare: main.cpp: In function 'std::vector<std::vector<int> > inmulteste(std::vector<std::vector<int> >, std::vector<std::vector<int> >)': main.cpp:14:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ans.size(); ++i){ ~~^~~~~~~~~~~~ main.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i){ ~~^~~~~~~~~~ main.cpp:18:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < b[0].size(); ++j){ ~~^~~~~~~~~~~~~ main.cpp:19:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < a.size(); ++k){ ~~^~~~~~~~~~