Compilare: main.c: In function 'main': main.c:24:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:25:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:27:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^~~~~~~~~~~~~~~~~~~~~~ main.c:30:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^~~~~~~~~~~~~~~~~~~~~~