Compilare: main.cpp: In function 'int main()': main.cpp:5:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("subset2.in","r",stdin); ^ main.cpp:6:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("subset2.out","w",stdout); ^ main.cpp:8:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld",&n,&k); ^