Compilare: user.cpp: In function ‘int main()’: user.cpp:9:13: warning: unused variable ‘d’ [-Wunused-variable] int n,i,d,prime=0,a,j; ^ user.cpp:9:23: warning: unused variable ‘a’ [-Wunused-variable] int n,i,d,prime=0,a,j; ^ user.cpp:7:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciur.in","r",stdin); ^ user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciur.out","w",stdout); ^ user.cpp:10:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^