Compilare: user.c: In function ‘main’: user.c:22:10: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid.in", "r", stdin); ^ user.c:23:10: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid.out", "w'", stdout); ^ user.c:24:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.c:27:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &m, &n, &h, &w); ^ user.c:30:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^