Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.
You must implement a solution with a linear runtime complexity and use only constant extra space.
Example 1:
- Input: nums = [2,2,3,2]
- Output: 3
Example 2:
- Input: nums = [0,1,0,1,0,1,99]
- Output: 99
Constraints:
- 1 <= nums.length <= 3 * 104
- -231 <= nums[i] <= 231 - 1
- Each element in nums appears exactly three times except for one element which appears once.