export function isIsomorphic(s: string, t: string): boolean {
  let ht: Record<string, string> = {};
  let ht2: Record<string, string> = {};
  if (s.length !== t.length) return false;

  for (let [index, key] of Object.entries(s)) {
    const currentValue = t[index];
    if (key in ht && currentValue !== ht[key]) return false;
    if (currentValue in ht2 && key !== ht2[currentValue]) return false;

    ht[key] = currentValue;
    ht2[currentValue] = key;
  }

  return true;
}