Find Minimum in Rotated Sorted Array

Suppose a sorted array is rotated at some pivot unknown to you beforehand.
(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).
Find the minimum element.
You may assume no duplicate exists in the array.
Solution:
1. public class Solution {
2. public int findMin(int[] a) {
3. return search(a, 0, a.length - 1);
4. }
5. 6. int search(int[] a, int lo, int hi) {
7. // a[] is sorted
8. if (lo > hi) {
9. return a[0];
10. }
11. 12. int mid = lo + (hi - lo) / 2;
13. 14. if (mid > 0 && a[mid - 1] > a[mid]) {
15. return a[mid];
16. }
17. 18. if (mid < a.length - 1 && a[mid] > a[mid + 1]) {
19. return a[mid + 1];
20. }
21. 22. if (a[mid] < a[hi]) {
23. return search(a, lo, mid - 1);
24. } else {
25. return search(a, mid + 1, hi);
26. }
27. }
28. }