Math Bit Manipulation
Learner Level

Implement the missingNumberXorImportant method that finds the missing number using XOR logic.

The input array nums contains size distinct numbers taken from the range 0 to size.

Exactly one number from this range is missing. Your task is to find and return that missing number.

For example, if the array is [3,0,1] and size is 3, the full range should be 0,1,2,3. The missing number is 2.

Example 1
Input:
nums (int[]) = [3,0,1]
size (int) = 3
Return:
(int) 2
Example 2
Input:
nums (int[]) = [0,1]
size (int) = 2
Return:
(int) 2
Example 3
Input:
nums (int[]) = [9,6,4,2,3,5,7,0,1]
size (int) = 9
Return:
(int) 8

Use XOR to remove matching values.

XOR has a useful property: a number XORed with itself becomes 0, and a number XORed with 0 remains unchanged. XOR all numbers from 0 to size, then XOR all values present in the array.

All numbers that appear in both places cancel out. The only value left is the missing number.

Pseudocode:

function missingNumberXorImportant(nums, size):
    result = 0
    for i from 0 to size:
        result = result XOR i
    for i from 0 to size - 1:
        result = result XOR nums[i]
    return result
Run your code to see the result.