Missing Ticket Number
Tickets were numbered 0 to n. You are given n distinct ticket numbers in tickets, in any order — exactly one number from the range is missing. Return it.
Aim for O(n) time and O(1) extra space.
Example 1
Input: tickets = [3, 0, 1] Output: 2
Example 2
Input: tickets = [0] Output: 1
Constraints
- 1 <= n <= 10^5
- All values are distinct and in [0, n].
Hint 1
The numbers 0..n add up to n(n+1)/2.
Hint 2
Subtract every ticket you have from that total.
Good practice for: Frontend Developer, Backend Developer, Full Stack Developer, Mobile App Developer, Game Developer, Automation Test Engineer
Run checks your code on 2 sample tests. Submit runs all 6 tests, including hidden ones, and earns points. Use console.log to debug. Python's first run can take a few seconds while it starts.