Compilare: user.cpp: In function ‘long long int doit(long long int, long long int)’: user.cpp:8:36: warning: value computed is not used [-Wunused-value] if (p < 0) doit(1/n, p * (-1)) % C; ^ user.cpp:13:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:18:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("modulo.in","r",stdin); ^ user.cpp:19:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("modulo.out","w",stdout); ^ user.cpp:21:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &A, &B, &C); ^