Compilare: user.cpp: In function ‘void read()’: user.cpp:40:38: 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:41:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d", &N, &M ) ; ^ user.cpp:43:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", &x ), Update( i, x ) ; ^ user.cpp:46:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", &op ) ; ^ user.cpp:48:55: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d", &x, &y ), Update( x, y ) ; ^ user.cpp:50:80: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d", &x, &y ), fout << Query(y) - Query(x - 1) << '\n' ; ^ user.cpp:52:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", &x), fout << Search(x) << '\n' ; ^