Bit Manipulation · Coding problem
Single Number
A free coding problem from the Bitwise Basics skill. Read it here, then solve it in the app in Java or Python.
- Easy
- Coding problem
- Free
- Java and Python
The problem
In nums, every value appears exactly twice except one. Return the value that appears only once.
Example
Input: nums = [7, 3, 5, 3, 7]
Output: 5
Solve it in O(n) time and O(1) extra space, so no hash set or map.
Constraints
1 <= nums.length <= 3 * 10^4-3 * 10^4 <= nums[i] <= 3 * 10^4- Every element appears exactly twice except for one
How it's graded
- Run checks your code against the examples. Submit also runs a hidden suite in four groups - basic cases, edge cases, random inputs and performance tests at the size limit - and shows which groups pass, never the hidden inputs.
- Stuck? Hints come in four steps, from a nudge to a code skeleton, each costing part of the points.
- Once you pass, you see the approaches from brute force to optimal, and where your solution lands among them.
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