Is XOR Operation in an Array easy or hard?

XOR Operation in an Array is classified as an Easy problem with a high acceptance rate around 87%. The iterative solution is straightforward, but recognizing the XOR mathematical pattern for the O(1) optimization adds an extra layer of insight.

XOR Operation in an Array Python/Java solution

In both Python and Java, the typical solution loops from 0 to n-1, computes start + 2*i, and applies the XOR operator to a running result. Python uses the ^ operator, and Java uses the same ^ bitwise XOR operator. The logic is identical across languages.

How to solve XOR Operation in an Array in O(n)?

Initialize a variable result = 0 and iterate from i = 0 to n - 1. For each iteration compute value = start + 2 * i and update result ^= value. After the loop finishes, result contains the XOR of all generated elements. This approach runs in O(n) time and O(1) space.

What is the best approach for XOR Operation in an Array?

The most efficient approach uses XOR mathematical patterns to compute the result in O(1) time and O(1) space. By transforming the sequence nums[i] = start + 2*i and applying the repeating pattern of XOR from 0 to n, the entire result can be calculated with constant-time formulas instead of iteration.

Is XOR Operation in an Array asked at Google/Amazon/Meta?

Problems involving XOR patterns and bit manipulation appear frequently in interviews at companies like Amazon, Google, and Meta. While this exact problem is considered easy, it tests understanding of XOR behavior and arithmetic sequences, which often appear in harder variations.

What data structure is used in XOR Operation in an Array?

No complex data structure is required. The problem relies primarily on bitwise XOR operations and simple arithmetic. The solution maintains a single integer accumulator, making it a pure bit manipulation and math problem rather than a data structure problem.

What is the time complexity of XOR Operation in an Array?

The straightforward solution runs in O(n) time by iterating from 0 to n-1 and XORing each computed value. An optimized mathematical approach reduces the time complexity to O(1) using XOR prefix patterns and arithmetic properties of the sequence.

Description Hints 1 Solution Video 13:25

1486. XOR Operation in an Array

Easy87.5% acceptance2 companies

You are given an integer n and an integer start.

Define an array nums where nums[i] = start + 2 * i (0-indexed) and n == nums.length.

Return the bitwise XOR of all elements of nums.

Example 1:

Input: n = 5, start = 0
Output: 8
Explanation: Array nums is equal to [0, 2, 4, 6, 8] where (0 ^ 2 ^ 4 ^ 6 ^ 8) = 8.
Where "^" corresponds to bitwise XOR operator.

Example 2:

Input: n = 4, start = 3
Output: 8
Explanation: Array nums is equal to [3, 5, 7, 9] where (3 ^ 5 ^ 7 ^ 9) = 8.

Constraints:

1 <= n <= 1000
0 <= start <= 1000
n == nums.length

Asked at 2 companies

Walmart Labs

Google

Topics

Bit Manipulation Math

Hints open one at a time

Hint 1

Simulate the process, create an array nums and return the Bitwise XOR of all elements of it.

13:25

Still stuck?Read 3 approaches, or watch a walkthrough.

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1class Solution:
2    def xorOperation(self, n: int, start: int) -> int:
3        

Starter codePython 3Spaces: 4

Examples

Case 1Case 2

Input

5
0

Input

4
3

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