Compilare: main.c: In function 'main': main.c:17:12: warning: unused variable 'i' [-Wunused-variable] int n, i, pas = (1 << 30), r = 0; ^ main.c:15:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("fact.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:16:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("fact.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:18:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^~~~~~~~~~~~~~~