Compilare: user.c: In function ‘main’: user.c:83:15: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘size_t {aka unsigned int}’ [-Wformat=] printf("%lu", dmax + 1); ^ user.c:60:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("darb.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:61:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("darb.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:63:5: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result] read(STDIN_FILENO, buf, CHUNK); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~