P9043 [PA 2021] Zbalansowane słowa

A string $s$ is defined to be good if and only if all characters contained in it appear the same number of times. Examples of good strings: `mama`, `aabbcbcccbaa`. Examples of bad strings: `ovo`. Given a string $s$, find the number of good **substrings** of $s$.

One line containing a string $s$.

One line containing an integer, representing the required value.

For $100\%$ of the testdata, $1 \leq |s| \leq 3 \times 10^5$, and $s$ contains only the three lowercase letters `a`, `b`, `c`. Translated by ChatGPT 5