如何按重复值拆分数组？

function splitArrayByDuplicates(arr) {
  const countMap = {};
  const result = [];

  // 统计每个元素的出现次数
  for (let i = 0; i < arr.length; i++) {
    const element = arr[i];
    countMap[element] = countMap[element] ? countMap[element] + 1 : 1;
  }

  // 拆分数组
  for (let i = 0; i < arr.length; i++) {
    const element = arr[i];
    const count = countMap[element];

    if (count > 1) {
      const subArray = Array(count).fill(element);
      result.push(subArray);
    }
  }

  return result;
}

// 示例用法
const arr = [1, 2, 2, 3, 4, 4, 4, 5, 5];
const splitResult = splitArrayByDuplicates(arr);
console.log(splitResult);