合并排序是建立在归并操作上的一种有效的排序算法。该算法是采用分治法（Divide and Conquer）的一个非常典型的应用。 合并排序法是将两个（或两个以上）有序表合并成一个新的有序表，即把待排序序列分为若干个子序列，每个子序列是有序的。然后再把有序子序列合并为整体有序序列。 将已有序的子序列合并，得到完全有序的序列；即先使每个子序列有序，再使子序列段间有序。若将两个有序表合并成一个有序表，称为2-路归并。合并排序也叫归并排序。-Merge Sort is an efficient sorting algorithm merge operation. The algorithm is a typical application of the divide-and-conquer method (Divide and Conquer). Merge sort method is to merge the two (or more) ordered table into a new ordered table to be sorted sequence is divided into a number of sub-sequences, each sub-sequence is ordered. Then put ordered subsequence combined into the overall ordered sequence. Merger will have been ordered sub-sequence, to obtain a complete orderly sequence　i.e. so that each first sub-sequence ordered, and then between the sub-sequence segment orderly. If you merge the two ordered list into an ordered table, known as the 2- way merge. The merger the sort also called merge sort.