Compilare: main.cpp: In function 'int main()': main.cpp:35:37: 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); ^ main.cpp:36:39: 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); ^ main.cpp:38:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld" , &n); ^ main.cpp: In function 'long long int bs(long long int)': main.cpp:31:12: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^~~~