Compilare: user.cpp: In function ‘void input()’: user.cpp:31:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%lld%lld%lld" , &n , &k , &w ) ; ^ user.cpp: In function ‘int main()’: user.cpp:55:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "nmult.in" , "r" , stdin ) ; ^ user.cpp:56:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "nmult.out" , "w" , stdout ) ; ^