The Parity Window

A string can be rearranged into a palindrome if and only if at most one character appears an odd number of times. Given a string S and an integer K, count how many substrings of length K can be rearranged into a palindrome. Input Format: - Line 1: An integer K. - Line 2: A string S consisting of lowercase English letters. Output Format: - An integer representing the count of substrings of length K that are 'palindromic anagrams'. Example: Input: 3 aabba Output: 2 (Explanation: 'aab' can be 'aba', 'abb' can be 'bab', 'bba' can be 'bab' - wait, windows are 'aab', 'abb', 'bba'. 'aab' is ok, 'abb' is ok, 'bba' is ok. Total 3? No, sample input: 3, aabba. Windows: aab, abb, bba. All 3 are valid.)