Compilare: user.c: In function ‘main’: user.c:6:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in","r",stdin),freopen("aria.out","w",stdout),scanf("%d",&n); ^ user.c:6:41: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in","r",stdin),freopen("aria.out","w",stdout),scanf("%d",&n); ^ user.c:6:70: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in","r",stdin),freopen("aria.out","w",stdout),scanf("%d",&n); ^ user.c:8:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&a[i],&b[i]); ^