Largest Unique Number — LeetCode 1133 Python Solution
EasyLeetCode PremiumArrayHash TableSorting
- Problem
- #1133
- Pattern
- Sorting
- Reading time
- 2 min
- Source
- leetcode.com
The problem
Given an integer array nums, return the largest integer that only occurs once. If no integer occurs once, return -1.
Example
- Input
- nums = [5,7,3,9,4,9,8,3,1]
- Output
- 8
- Explanation
- The maximum integer in the array is 9 but it is repeated. The number 8 occurs only once, so it is the answer.
Python solution
Python
class Solution:
def largestUniqueNumber(self, nums: List[int]) -> int:
cnt = Counter(nums)
return max((x for x, v in cnt.items() if v == 1), default=-1)Complexity
| Measure | Complexity |
|---|---|
| Time | O(n + M) |
| Space | O(M) auxiliary |
Pattern: Sorting
Spend O(n log n) once to buy an ordering that makes the rest of the problem trivial. LeetCode 1133. Largest Unique Number is filed here because LeetCode tags it Sorting, which is the vocabulary this hub collects.
The sorting guide has the Python template for the pattern and the 401 LeetCode problems that use it.
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Frequently asked questions
- How hard is LeetCode 1133. Largest Unique Number?
- LeetCode 1133. Largest Unique Number is rated Easy on LeetCode.
- What is the time complexity of LeetCode 1133. Largest Unique Number?
- The Python solution on this page runs in O(n + M).
- What is the space complexity of LeetCode 1133. Largest Unique Number?
- The Python solution on this page uses O(M) auxiliary space.
- What topics does LeetCode 1133. Largest Unique Number cover?
- LeetCode 1133. Largest Unique Number is tagged Array, Hash Table and Sorting on LeetCode.
- Is LeetCode 1133. Largest Unique Number a premium problem?
- Yes. LeetCode 1133. Largest Unique Number is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.