Compilare: main.cpp: In function 'int main()': main.cpp:23:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<prime.size() && prime[i]*prime[i] <= b;++i){ ~^~~~~~~~~~~~~ main.cpp:34:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<divi.size();++i) ~^~~~~~~~~~~~