Compilare: user.cpp: In function ‘bool checkPrim(long long int)’: user.cpp:16:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else for(int i=0;i<prim.size(),i<=sqrt(n);++i)if(n%prim[i]==0)return false; ^ user.cpp:16:23: warning: value computed is not used [-Wunused-value] else for(int i=0;i<prim.size(),i<=sqrt(n);++i)if(n%prim[i]==0)return false; ^