Suppose an array sorted in ascending order 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.
Your algorithm's runtime complexity must be in the order of O(log n).
Example 1:
Input: nums = [4,5,6,7,0,1,2], target = 0
Output: 4
Example 2:
Input: nums = [4,5,6,7,0,1,2], target = 3
Output: -1
class Solution {
public int search(int[] nums, int target) {
int low = 0, high = nums.length - 1;
while (low <= high) {
int mid = low + (high - low) / 2;
if (nums[mid] == target)
return mid;
// If left part is sorted
if (nums[low] <= nums[mid]) {
if (target >= nums[low] && target < nums[mid])
high = mid - 1;
else
low = mid + 1;
}
// If right part is sorted
else {
if (target > nums[mid] && target <= nums[high])
low = mid + 1;
else
high = mid - 1;
}
}
return -1;
}
}