Compilare: user.cpp: In function ‘int main()’: user.cpp:14:14: warning: statement has no effect [-Wunused-value] for(n;n>=3;n--) ^ user.cpp:5:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nunta.in","r",stdin); ^ user.cpp:6:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nunta.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); ^