No. 67 随机生成一个长度为 10 的整数类型的数组，例如 [2, 10, 3, 4, 5, 11, 10, 11, 20]，将其排列成一个新数组，要求新数组形式如下，例如 [[2, 3, 4, 5], [10, 11], [20]]。

const create = () =>
  new Array(10).fill("_").map(() => parseInt(99 * Math.random()));
const handler = (arr) => {
  let output = [],
    i = -1,
    edge;
  arr
    .sort((a, b) => a - b)
    .forEach((item) => {
      let sItem = "" + item,
        newEdge;
      1 === sItem.length ? (newEdge = 9) : (newEdge = sItem[0] + "9");
      if (edge !== newEdge) {
        i++;
        edge = newEdge;
        output.push([]);
      }
      output[i].push(item);
    });
  return output;
};
console.log(handler(a));
console.log(handler(create()));