Compilare: user.c: In function ‘main’: user.c:33:12: warning: variable ‘n’ set but not used [-Wunused-but-set-variable] int i, n, m, x, y, u, v, s, qt, qh; ^ user.c:35:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:36:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:38:5: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result] read(STDIN_FILENO, buf, CHUNK); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~