Compilare: main.cpp: In function 'int Verifica(int)': main.cpp:45:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();++j) ~^~~~~~~~~~~~ main.cpp: In function 'void Back(int)': main.cpp:97:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k<nr_prim.size()-1) Back(k+1); ~^~~~~~~~~~~~~~~~~ main.cpp:99:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(k<nr_prim.size()-1)Back(k+1); ~^~~~~~~~~~~~~~~~~