Compilare: main.c: In function 'main': main.c:53:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("algsort.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:54:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("algsort.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:56:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^~~~~~~~~~~~~~~ main.c:58:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^~~~~~~~~~~~~~~~~~