Compilare: user.cpp: In function ‘int main()’: user.cpp:254:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v1.size(); i++) ^ user.cpp:262:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v2.size(); i++) ^ user.cpp:272:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v1.size(); i++) ^ user.cpp:280:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v2.size(); i++) ^