Compilare: user.cpp: In function ‘int main()’: user.cpp:26:10: warning: statement has no effect [-Wunused-value] for(i;i<n;i+=2){ ^ user.cpp:6:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oras.in","r",stdin); ^ user.cpp:7:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oras.out","w",stdout); ^ user.cpp:9:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^