algorythms
Bitwise XOR
LC #260Medium

Single Number III

Bitwise XOR
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Problem

Two elements appear once, all others appear twice. Find those two elements.

arraybit-manipulation

Constraints

  • 2 ≤ n ≤ 3 × 10⁴
  • -2³¹ ≤ nums[i] ≤ 2³¹ − 1
  • Exactly two elements appear once; all others appear twice
  • O(1) extra space required

Example

Inputnums = [1, 2, 1, 3, 2, 5]
Output[3, 5]
Why

3 and 5 appear once. All others appear twice. XOR all → 3^5, then split

Hints — reveal one at a time