Find Words That Can Be Formed by Characters

export function countCharacters(words: string[], chars: string): number {
  const createCounter = (chars: string) => {
    const counter = new Map<string, number>();
    for (const char of chars) {
      counter.set(char, (counter.get(char) ?? 0) + 1);
    }
    return counter;
  };
 
  const charCounter = createCounter(chars);
 
  const isGoodWord = (word: string) => {
    const wordCounter = createCounter(word);
    for (const [char, count] of wordCounter.entries()) {
      const charCount = charCounter.get(char) ?? 0;
      if (charCount < count) {
        return false;
      }
    }
    return true;
  };
 
  return words.reduce((prev, word) => (isGoodWord(word) ? prev + word.length : prev), 0);
}