Given a string, find the longest subsequence consisting of a single character. Example: longest("ABAACDDDBBA") should return {'D': 3}.
const str = "AABCDDBBBEA"; function longest (str) { let max_count = 0, count = 0, max_char = null, prv_char = null; for (let current of str) { if (current === prv_char) { count++ } else { count = 1; } if (count > max_count) { max_count = count; max_char = current; } prv_char = current; } return {[max_char]: max_count}; } console.log(longest(str)) // {B: 3}