Compilare: user.c: In function ‘main’: user.c:18:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("proc.in", "r", stdin); ^ user.c:19:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("proc.out", "w", stdout); ^ user.c:20:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &unu, &p); ^