K - Magical String

You have been given a string $S$ of size $N$ which consists of **uppercase characters** only. A $K$-Magical String is a string in which the longest **non - decreasing subsequence** is of size exactly $K$. You have been given $Q$ queries where each query is in the form $L, R,$ and $K$. For each query, check whether substring from index $L$ to index $R$ can be converted into a $K$-Magical String o