Recover Rotated Sorted Array

Given a rotated sorted array, recover it to sorted array in-place.

Clarification

What is rotated array?

• For example, the orginal array is [1,2,3,4], The rotated array of it can be [1,2,3,4], [2,3,4,1], [3,4,1,2], [4,1,2,3]

Example

[4, 5, 1, 2, 3] -> [1, 2, 3, 4, 5]

分析：

利用公式 (A^TB^T)^T = BA

 public class Solution {

     public void recoverRotatedSortedArray(ArrayList<Integer> nums) {
         if (nums == null || nums.size() ==  || nums.size() == ) return;
         int i = ;
         for (; i < nums.size() - ; i++) {
             if (nums.get(i) > nums.get(i + ))
                 break;
         }
         if (i == nums.size() - ) return;
         reverse(nums, , i);
         reverse(nums, i + , nums.size() - );
         reverse(nums, , nums.size() - );
     }

     public void reverse(ArrayList<Integer> nums, int l, int r) {
         while (l < r) {
             int temp = nums.get(l);
             nums.set(l, nums.get(r));
             nums.set(r, temp);
             l++;
             r--;
         }
     }
 }