540. Single Element in a Sorted Array

Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element that appears only once.

Example 1:

Input: [1,1,2,3,3,4,4,8,8]
Output: 2

Example 2:

Input: [3,3,7,7,10,11,11]
Output: 10

Note: Your solution should run in O(log n) time and O(1) space.

Subscribe to see which companies asked this question.
public class Solution {
public int singleNonDuplicate(int[] nums) {
int start = 0;
int end = nums.length - 1;
int mid = start + (end - start) / 2;
while (start < end) {
mid = start + (end - start) / 2;
if (nums[mid] == nums[mid + 1]) {
if ((mid & 1) == 0)
start = mid + 2;
else
end = mid - 1;
} else if (nums[mid] == nums[mid - 1]) {
if ((mid & 1) != 0)
start = mid + 1;
else
end = mid - 2;
} else
return nums[mid];
}
return nums[end];
}
}