Recover Rotated Sorted Array

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

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Example

[4, 5, 1, 2, 3] -> [1, 2, 3, 4, 5]

Challenge

In-place, O(1) extra space and O(n) time.

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]

 1     public void recoverRotatedSortedArray(ArrayList<Integer> nums)
 2     {
 3         // write your code
 4         if(nums.size()==0||nums.size()==1) return;
 5         int i =0;
 6         for(i=0; i<nums.size()-1;i++)
 7         {
 8             if(nums.get(i)>nums.get(i+1)) break;
 9         }
10         if(i == nums.size()-1) return;
11         reverse(nums,0,i);
12         reverse(nums,i+1,nums.size()-1);
13         reverse(nums,0,nums.size()-1);
14         return;
15
16
17     }
18
19
20     public void reverse(ArrayList<Integer> nums, int left, int right)
21     {
22         while(left<right)
23         {
24             int temp = nums.get(left);
25             nums.set(left,nums.get(right));
26             nums.set(right,temp);
27             left++;
28             right--;
29
30         }
31
32         return;
33     }