题解 | #快速排序#

      const _quickSort = (arr) => {
        if (arr.length <= 1) return arr;
        const point = arr[0];
        let left = [];
        let right = [];
        for (let i = 1; i < arr.length; i++) {
          if (arr[i] < point) {
            left.push(arr[i]);
          } else {
            right.push(arr[i]);
          }
        }
        return _quickSort(left).concat(point, _quickSort(right));
      };