2484. Count Palindromic Subsequences

Given a string of digits s, return the number of palindromic subsequences of s having length 5. Since the answer may be very large, return it modulo 109 + 7. Note: - A string is palindromic if it reads the same forward and backward. - A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters. Exa