Single Number — LeetCode 136 Python Solution
EasyBit ManipulationArray
- Problem
- #136
- Pattern
- Bit Manipulation
- Reading time
- 2 min
- Source
- leetcode.com
The problem
Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.
Python solution
Python
class Solution:
def singleNumber(self, nums: List[int]) -> int:
return reduce(xor, nums)Complexity
| Measure | Complexity |
|---|---|
| Time | O(n), where n is the length of the array |
| Space | O(1) auxiliary |
Pattern: Bit Manipulation
Use XOR, masks and the low-bit trick to replace whole data structures with an integer. LeetCode 136. Single Number is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Bit Manipulation.
The bit manipulation guide has the Python template for the pattern and the 194 LeetCode problems that use it.
Related problems
On study lists
This problem is on NeetCode 150, LeetCode 75 and Top Interview 150.
Frequently asked questions
- How hard is LeetCode 136. Single Number?
- LeetCode 136. Single Number is rated Easy on LeetCode.
- What is the time complexity of LeetCode 136. Single Number?
- The Python solution on this page runs in O(n), where n is the length of the array.
- What is the space complexity of LeetCode 136. Single Number?
- The Python solution on this page uses O(1) auxiliary space.
- What topics does LeetCode 136. Single Number cover?
- LeetCode 136. Single Number is tagged Bit Manipulation and Array on LeetCode.