Coding Interview PatternsSingle Number III
MediumBitwise Manipulation
Single Number III
Explanation & Solution
Description
Given an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order.
You must write an algorithm that runs in linear runtime complexity and uses only constant extra space.
Input:nums = [1,2,1,3,2,5]
0
1
1
2
2
1
3
3
4
2
5
5
Output:[3,5]
0
3
1
5
Explanation: [5,3] is also a valid answer.
Constraints
2 <= nums.length <= 3 * 10^4-2^31 <= nums[i] <= 2^31 - 1- Each integer in nums will appear twice, only two integers will appear once.
Approach
Bitwise Manipulation pattern
Key Insight
- By finding a bit where the two unique numbers differ, we can partition the array into two groups and apply the Single Number I trick to each group
- Time: O(n) | Space: O(1)
Visualization
Input:
[1, 2, 1, 3, 2, 5]
—
No animation available
Left (L)Right (R)ConvergedDone
0 steps