Compilare: user.cpp: In function ‘int prime(int)’: user.cpp:7:9: warning: unused variable ‘i’ [-Wunused-variable] int i,x; ^ user.cpp:7:11: warning: unused variable ‘x’ [-Wunused-variable] int i,x; ^ user.cpp: In function ‘int main()’: user.cpp:32:17: warning: pointer to a function used in arithmetic [-Wpointer-arith] out<<prime[n]<<endl; ^