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
Solution:
using System;
using System.Collections.Generic;
using System.Text;
namespace LeetCode.AskGif.Easy.Array
{
public class XorOperationSoln
{
public int XorOperation(int n, int start)
{
int num = 0;
int xor = 0;
for (int i = 0; i < n; i++)
{
num = start + 2 * i;
xor = xor ^ num;
}
return xor;
}
}
}
Time Complexity: O(n)
Space Complexity: O(1)
Unit Tests:
using LeetCode.AskGif.Easy.Array;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Collections.Generic;
using System.Text;
namespace CodingUnitTest.Easy.Array
{
[TestClass]
public class XorOperationSolnTests
{
[TestMethod]
public void XorOperationSoln_First()
{
var n = 5;
var start = 0;
var expected = 8;
var res = new XorOperationSoln().XorOperation(n, start);
Assert.AreEqual(expected, res);
}
[TestMethod]
public void XorOperationSoln_Second()
{
var n = 4;
var start = 3;
var expected = 8;
var res = new XorOperationSoln().XorOperation(n, start);
Assert.AreEqual(expected, res);
}
[TestMethod]
public void XorOperationSoln_Third()
{
var n = 1;
var start = 7;
var expected = 7;
var res = new XorOperationSoln().XorOperation(n, start);
Assert.AreEqual(expected, res);
}
[TestMethod]
public void XorOperationSoln_Fourth()
{
var n = 10;
var start = 5;
var expected = 2;
var res = new XorOperationSoln().XorOperation(n, start);
Assert.AreEqual(expected, res);
}
}
}
