[LeetCode] Search in Rotated Sorted Array

Total Accepted: 11464 Total Submissions: 40857

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

).

You are given a target value to search. If found in the array return its index, otherwise return -1.

You may assume no duplicate exists in the array.

public class Solution {
public int search(int[] A, int target) {
int lo = 0;
int hi = A.length - 1;
int mid = 0;

while (lo <= hi) {
mid = (lo + hi) >> 1;

if      (target == A[mid]) return mid;
else if (A[lo] <= A[mid]) {
if (target >= A[lo] && target < A[mid]) hi = mid - 1;
else lo = mid + 1;
}
//else if (A[mid] < A[hi])
else {
if (target > A[mid] && target <= A[hi]) lo = mid + 1;
else hi = mid -1;
}
}

return -1;
}
}