Compilare: user.cpp: In function ‘int main()’: user.cpp:56:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[(i&1)^1].size();j++) ^ user.cpp:95:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i&1].size();j++) ^ user.cpp:102:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[n&1].size();i++) ^