Compilare: user.cpp: In function ‘int main()’: user.cpp:13:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;(1<<i)<=b;++i) ^ 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("modulo.in","r",stdin); ^ user.cpp:8:37: 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:11:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lu%lu%d",&a,&b,&c); ^