This is the last problem of this contest, so Rikka doesn't want to add a lengthy background to it. Let us make all the things simple and clear.
You have a string $s$ of length $n$ which only contains lowercase English letters from a to l (There are $12$ possible letters). You can choose a permutation of these $12$ letters $p_a,p_b,...,p_l$ and then you can get a string $t = p_{s_1}p_{s_2}...p_{s_n}$. Your task is to check whether the $i$th suffix (the substring $s[i,n]$) can become the largest suffix in lexicographic order after this modification.