Compilare: user.cpp: In function ‘int main()’: user.cpp:41:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0 ; j < sol.size(); j++) ^ user.cpp:48:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < v.size(); k++) ^ user.cpp:55:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ^