Compilare: main.c: In function 'main': main.c:17:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:18:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("aria.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^~~~~~~~~~~~~~~ main.c:22:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf", &a[i].x, &a[i].y); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~