Compilare: user.cpp: In function ‘int main()’: user.cpp:21:13: warning: unused variable ‘i’ [-Wunused-variable] int n , i , j ; ^ user.cpp:21:17: warning: unused variable ‘j’ [-Wunused-variable] int n , i , j ; ^ user.cpp:19:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "tg.in" , "r" , stdin ) ; ^ user.cpp:20:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "tg.out" , "w" , stdout ) ; ^ user.cpp:22:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , &n ) ; ^