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260. Single Number III

MediumOpen on LeetCodeProblem statement

Problem Statement

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:

Java

Source file
class Solution {
    public int[] singleNumber(int[] nums) {
        int xor = 0;
        for (int n : nums)
            xor ^= n;
        int diff = xor & -xor; // find set bit for masking

        int ans1 = 0;
        for (int n : nums)
            if ((n & diff) == 0)
                ans1 ^= n;

        return new int[] { ans1, ans1 ^ xor };
    }
}