1486. XOR Operation in an Array #

Problem #

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.

Example 3:

Input: n = 1, start = 7
Output: 7

Example 4:

Input: n = 10, start = 5
Output: 2

Constraints:

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

Problem Summary #

Given two integers, n and start. The array nums is defined as: nums[i] = start + 2*i (0-indexed), and n == nums.length. Return the result obtained by bitwise XORing all elements in nums.

Solution Approach #

• Easy problem. According to the problem statement, use one loop to cumulatively XOR each element in the array in order.

Code #

package leetcode

func xorOperation(n int, start int) int {
	res := 0
	for i := 0; i < n; i++ {
		res ^= start + 2*i
	}
	return res
}