Compilare: user.cpp: In function ‘int main()’: user.cpp:15:9: warning: unused variable ‘lim’ [-Wunused-variable] int lim =( int ) sqrt ( ( double ) y ) ; ^ user.cpp:11:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("magicnum.in" , "r" , stdin ); ^ user.cpp:12:47: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("magicnum.out" , "w" , stdout ); ^ user.cpp:14:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d" , &x , &y ); ^