res to 0 to store the result (number of equal count substrings).s and store it in max_unique.unique from 1 to max_unique.unique, calculate the window size len as count * unique.cnt to store the count of each character within the window.has_count to 0 to store the number of characters that have exactly count occurrences in the window.s.cnt and update has_count accordingly.len, decrease the count of the character at the start of the window and update has_count.has_count equals unique, increment res.res as the final result.