260. Single Number III

中文文档

Description

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.

Follow up: Your algorithm should run in linear runtime complexity. Could you implement it using only constant space complexity?

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.

Solutions

Python3

class Solution:
    def singleNumber(self, nums: List[int]) -> List[int]:
        eor = 0
        for num in nums:
            eor ^= num
        diff = eor & (~eor + 1)
        a = 0
        for num in nums:
            if (num & diff) == 0:
                a ^= num
        b = eor ^ a
        return [a, b]

Java

class Solution {
    public int[] singleNumber(int[] nums) {
        int eor = 0;
        for (int num : nums) {
            eor ^= num;
        }
        int diff = eor & (~eor + 1);
        int a = 0;
        for (int num : nums) {
            if ((num & diff) == 0) {
                a ^= num;
            }
        }
        int b = eor ^ a;
        return new int[]{a, b};
    }
}

...