DEV Community

Cover image for 260. Single Number III
MD ARIFUL HAQUE
MD ARIFUL HAQUE

Posted on • Edited on

1

260. Single Number III

260. Single Number III

Medium

Given an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order.

You must write an algorithm that runs in linear runtime complexity and uses only constant extra space.

Example 1:

  • Input: nums = [1,2,1,3,2,5]
  • Output: [3,5]
  • Explanation: [5, 3] is also a valid answer.

Example 2:

  • Input: nums = [-1,0]
  • Output: [-1,0]

Example 3:

  • Input: nums = [0,1]
  • Output: [1,0]

Constraints:

  • 2 <= nums.length <= 3 * 104
  • -231 <= nums[i] <= 231 - 1
  • Each integer in nums will appear twice, only two integers will appear once.

Solution:

class Solution {

    /**
     * @param Integer[] $nums
     * @return Integer[]
     */
    function singleNumber($nums) {
        $xors = array_reduce($nums, function($carry, $item) { return $carry ^ $item; }, 0);
        $lowbit = $xors & -$xors;
        $ans = array_fill(0, 2, 0);

        foreach ($nums as $num) {
            if ($num & $lowbit) {
                $ans[0] ^= $num;
            } else {
                $ans[1] ^= $num;
            }
        }

        return $ans;

    }
}
Enter fullscreen mode Exit fullscreen mode

Contact Links

If you found this series helpful, please consider giving the repository a star on GitHub or sharing the post on your favorite social networks 😍. Your support would mean a lot to me!

If you want more helpful content like this, feel free to follow me:

Image of Datadog

The Future of AI, LLMs, and Observability on Google Cloud

Datadog sat down with Google’s Director of AI to discuss the current and future states of AI, ML, and LLMs on Google Cloud. Discover 7 key insights for technical leaders, covering everything from upskilling teams to observability best practices

Learn More

Top comments (0)

Sentry image

See why 4M developers consider Sentry, “not bad.”

Fixing code doesn’t have to be the worst part of your day. Learn how Sentry can help.

Learn more