Compilare: user.cpp: In function ‘void bf(int, int)’: user.cpp:16:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:43:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[i].size()<minn) {minn=v[i].size(); poz=i;} ^