Problem Statement

For a string s consisting only of characters '0' and '1', determine the number of subsequences of length 5 that are palindromes. Since the result can be very large, return the answer modulo (10 9 + 7). Notes: A palindrome is a sequence that reads the same backward as forward. A subsequence is obtained from the given sequence by deleting zero or more elements without changing the order of the remaining elements. Two subsequences are considered different if the indices used to form them are different. Example s = "0100110" Using 1-based indexing, the 5 subsequences are indices (1, 2, 3, 6, 7) → 01010 indices (1, 2, 3, 5, 7) → 01010 indices (1, 2, 4, 6, 7) → 01010 indices (1, 2, 4, 5, 7) → 01010 indices (1, 2, 5, 6, 7) → 01110 5 modulo (10 9 + 7) = 5 Function Description Complete the function getPalindromesCount in the editor with the following parameter: string s : the binary string Returns int : the number of subsequences of length 5 which are palindromes, modul