SRM 670 div2 B BearSlowlySorts

   Problem Statement  
 Problem Statement for BearSlowlySorts

Problem Statement

 

Limak is a little polar bear. He has a int[] w containing a sequence of N distinct numbers. He wants to sort this sequence into ascending order.

Limak knows some fast sorting algorithms but in the real world such knowledge sometimes isn't enough. In order to sort the sequencew Limak must physically move the numbers into their correct places. Such a thing can be hard for a little bear.

In a single move Limak can take all elements he can reach and sort them into ascending order. The problem is that Limak's arms are too short. Regardless of where he stands, he can only reach N-1 consecutive elements of w. Hence, in each move he can either sort all elements except for the last one, or all elements except for the first one.

Limak can make the moves in any order he likes. Compute and return the smallest number of moves necessary to sort the given sequencew.

 

Definition

 Class:BearSlowlySortsMethod:minMovesParameters:int[]Returns:intMethod signature:int minMoves(int[] w)(be sure your method is public)   

Constraints

-w will contain between 3 and 50 elements, inclusive.-Each element in w will be between 1 and 1000, inclusive.-w will contain distinct elements. 

Examples

0) 

{2,6,8,5}

Returns: 1

Limak can sort this sequence in a single move. All he needs to do is to sort all elements except for the first one. In this single move Limak will pick up the elements {6,8,5} and reorder them into {5,6,8}. This will change the given w into {2,5,6,8}, and that is a sorted sequence.1)  

{4,3,1,6,2,5}

Returns: 2

One of the shortest ways is to sort first N-1 numbers first to get {1,2,3,4,6,5} and then to sort the last N-1 numbers.2)  

{93,155,178,205,213,242,299,307,455,470,514,549,581,617,677}

Returns: 0

This sequence is already sorted, no moves are necessary.3)  

{50,20,30,40,10}

Returns: 3

4)  

{234,462,715,596,906,231,278,223,767,925,9,526,369,319,241,354,317,880,5,696}

Returns: 2

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This problem was used for: 
       Single Round Match 673 Round 1 - Division II, Level Two

题意：给你一个序列，每次操作最多对n-1个元素排序，问最少几次操作能使序列变成升序。

分四种情况

情况一：本来就是升序的

直接返回0

情况二：最大的在最后或者最小的在最前面

这种情况只要操作一次即可。

返回1

情况三：最小的在最后，最大的在最前面

把最大值或者最小值通过一次操作，使其到中间位置。

这就变成情况二了

返回3

情况四：其他

首先把不是在两端的最大值或者最小值通过一次操作，使其到最前面或者最后。

然后就是第二种情况了

返回二

做题时太浮躁了搞了半天才A