Compilare: user.c: In function ‘bkt’: user.c:32:12: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (valid(k)==1) ^ user.c: In function ‘main’: user.c:44:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin); ^ user.c:45:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.out","w",stdout); ^ user.c:46:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^