A string made of an even number of characters (“<” and/or “>”) is called symmetric if all characters in its first half are “<” and all characters in its second half are “>”. Examples of symmetric strings are: “” (empty string), “<>”, “<<>>”, “<<<>>>”, etc. Write a function: function solution(S); that, given a string S made of N characters (“<“, “>” and/or “?”)”, returns the length of the longest symmetric substring that can be obtained after replacing question marks with “<” or “>” characters. Examples: 1. For S =”<>>”, after replacing all question marks with “<“, the string “<><<<>>” is obtained. Its longest symmetric substring is “<<>>”, so the function should return 4. 2. For S = “??????”, the optimal option is to replace the first three question marks with “<” and the next three question marks with “>” thus obtaining the string “<<<>>>”. The function should return 6. 3. For S =”<‘ and/or ‘?’.
