Compilare: user.cpp: In function ‘int main()’: user.cpp:53:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "aib.in" , "r" , stdin ) ; ^ user.cpp:54:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "aib.out" , "w", stdout ) ; ^ user.cpp:56:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d " , &N , &M ) ; ^ user.cpp:60:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d " , &X ) ; ^ user.cpp:66:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d " , &op ) ; ^ user.cpp:71:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d " , &a , &b ) ; ^ user.cpp:75:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d " , &a , &b ) ; ^ user.cpp:79:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , &a ) ; ^