每一趟从待排序的数据元素中选出最小（或最大）的一个元素，顺序放在已排好序的数列的最后，直到全部待排序的数据元素排完。

-Each trip from the data elements to be sorted to select the minimum (or maximum) of an element, the order has been sorted on the number of columns in the end, until all the data elements to be sorted row end.