Compilare: user.cpp: In function ‘long long int cifra(long long int)’: user.cpp:8:26: warning: unused variable ‘i’ [-Wunused-variable] long long int s, p = 5, i; ^ user.cpp: In function ‘int main()’: user.cpp:21:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fact.in", "r", stdin); ^ user.cpp:22:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fact.out", "w", stdout); ^ user.cpp:24:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &n); ^