Compilare: user.c: In function ‘fadiferenta’: user.c:30:9: warning: unused variable ‘c’ [-Wunused-variable] int c=0, i, z; ^ user.c: In function ‘main’: user.c:107:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("largestroot.in", "r", stdin); ^ user.c:108:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("largestroot.out", "w", stdout); ^ user.c:123:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.c:128:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.c:139:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &cc); ^ user.c:141:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &cc); ^ user.c:145:22: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &cc); ^ user.c:153:22: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &cc); ^