Compilare: user.c: In function ‘init’: user.c:7:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("adunare.in", "r", stdin); ^ user.c:8:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("adunare.out", "w", stdout); ^ user.c:10:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^