fast_sort

  /*快速排序：以待排序元素中的第一个元素作为基准将带排序的元素分为三组 *大于基准元素为一组置于基准值的右边，小于基准值的元素为一组置于基准值的左边， *基准值为一组，这样就找到了基准元素的位置就确定了 *如此递归调用。直到每一组的low==high，即实现了排序的要求。 */ (/* Rapid Sort: the first element to be sorted in the element as a basis with with sorting the elements are divided into three groups* is greater than the reference element of a group is placed on the right side of the reference value, smaller than the reference value elements for a group of placed on the left side of the reference value,* reference value, a group, so that the location of the reference element is found it is determined* so recursive call. Until each group of low == high to achieve the requirements of the sort.* /)