Compilare: user.c: In function ‘length’: user.c:13:5: warning: statement with no effect [-Wunused-value] for( nr; nr >=1; nr--){ ^ user.c: In function ‘main’: user.c:26:5: warning: statement with no effect [-Wunused-value] for (q;q!=0; q--){ ^ user.c:24:15: warning: unused variable ‘nr’ [-Wunused-variable] int i,j,k,nr=0; ^ user.c:24:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k,nr=0; ^ user.c:24:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,k,nr=0; ^ user.c:22:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("oluna.in","r",stdin); ^ user.c:23:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("oluna.out","w",stdout); ^ user.c:25:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &q); ^ user.c:27:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^