export function longestPalindrome(s: string): string {
  let bestCandidate = ''

  function expand(left: number, right: number): string {
    // Expand while inside bounds and left/right charactes match
    while (left >= 0 && right < s.length&& s[left] === s[right]) {
      left--
      right++
    }

    return s.slice(left + 1, right)
  }
  
  for (let i = 0; i < s.length; i++) {
    const odd = expand(i, i)
    const even = expand(i, i + 1)

    if (odd.length > bestCandidate.length) bestCandidate = odd
    if (even.length > bestCandidate.length) bestCandidate = even
  }

  return bestCandidate;
}