题目如下：
Problem D: ShellSort
He made each turtle stand on another one‘s back
And he piled them all up in a nine-turtle stack.
And then Yertle climbed up. He sat down on the pile.
What a wonderful view! He could see ‘most a mile!
The Problem
King Yertle wishes to rearrange his turtle throne to place his highest-ranking nobles and closest advisors nearer to the top. A single operation is available to change the order of the turtles in the stack: a turtle can crawl out of its position in the stack
and climb up over the other turtles to sit on the top.
Given an original ordering of a turtle stack and a required ordering for the same turtle stack, your job is to determine a minimal sequence of operations that rearranges the original stack into the required stack.
The first line of the input consists of a single integer K giving the number of test cases. Each test case consist on an integer n giving the number of turtles in the stack. The next n lines specify the original ordering of the turtle stack. Each of the lines
contains the name of a turtle, starting with the turtle on the top of the stack and working down to the turtle at the bottom of the stack. Turtles have unique names, each of which is a string of no more than eighty characters drawn from a character set consisting
of the alphanumeric characters, the space character and the period (`.‘). The next n lines in the input gives the desired ordering of the stack, once again by naming turtles from top to bottom. Each test case consists of exactly 2n+1 lines in total. The number
of turtles (n) will be less than or equal to two hundred.
For each test case, the output consists of a sequence of turtle names, one per line, indicating the order in which turtles are to leave their positions in the stack and crawl to the top. This sequence of operations should transform the original stack into the
required stack and should be as short as possible. If more than one solution of shortest length is possible, any of the solutions may be reported. Print a blank line after each test case.
Sample Input
2
3
Yertle
Duke of Earl
Sir Lancelot
Duke of Earl
Yertle
Sir Lancelot
9
Yertle
Duke of Earl
Sir Lancelot
Elizabeth Windsor
Michael Eisner
Richard M. Nixon
Mr. Rogers
Ford Perfect
Mack
Yertle
Richard M. Nixon
Sir Lancelot
Duke of Earl
Elizabeth Windsor
Michael Eisner
Mr. Rogers
Ford Perfect
Mack
Sample Output
Duke of Earl
Sir Lancelot
Richard M. Nixon
Yertle
这题要求将一堆乱序的乌龟排成题目要求的顺序，乌龟只能移到第一个，要求输出移动的乌龟，并且要求操作最少，自己的老是超时，网上参考了别人的代码（），发现了该问题的本质，就是从下到上遍历目标序列，找到第一个在乱序中的下标大于目标序列下标的乌龟，这样剩下的乌龟只要按照目标序列的顺序依次移动即可。找到第一个乌龟的过程中，满足保序性（姑且这么说），就是在乱序数组的循环变量只能不断往下降，所以两个数组中判断过的乌龟顺序一致，等会儿把第一个乌龟以上的乌龟都移动后这些乌龟一定会对应起来。代码很简单。
AC的代码如下：
UVA ShellSort