Keep adding one book at a time to the sorted sub-line, comparing and swapping the new book with the one before it until it's correctly placed among the books sorted so far.

每次将一本书插入之前已经排列好的队伍中，与前面相邻的一本书进行对比并判断是否交换，直到这本书到达队伍中正确的位置。