Compilare: user.c: In function ‘main’: user.c:5:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("lkperm.in","r",stdin),freopen("lkperm.out","w",stdout),scanf("%d%d%d",&n,&l,&k),h[0]=d[0]=1; ^ user.c:5:43: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("lkperm.in","r",stdin),freopen("lkperm.out","w",stdout),scanf("%d%d%d",&n,&l,&k),h[0]=d[0]=1; ^ user.c:5:74: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("lkperm.in","r",stdin),freopen("lkperm.out","w",stdout),scanf("%d%d%d",&n,&l,&k),h[0]=d[0]=1; ^