Compilare: user.c: In function ‘main’: user.c:31:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("unlock.in","r",stdin); ^ user.c:32:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("unlock.out","w",stdout); ^ user.c:34:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&t); ^ user.c:36:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i",&n,&m,&k); nm=n*m; ++k; ^ user.c:45:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&A[c]); ^