Description:
Given an array of numbers 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.
For example:
Given nums = [1, 2, 1, 3, 2, 5]
, return [3, 5]
.
Note:
- The order of the result is not important. So in the above example,
[5, 3]
is also correct. - Your algorithm should run in linear runtime complexity. Could you implement it using only constant space complexity?
Code:
vector<int> singleNumber(vector<int>& nums) { vector<int>result; if (nums.size() < 2) return result; int xorAll = 0; for (int i = 0; i < nums.size(); ++i) xorAll^=nums[i]; unsigned int x = 1; while ((xorAll & x) == 0) { x=x<<1; } int result1=0,result2=0; for (int j = 0; j < nums.size(); ++j) { if ((nums[j]&x) == 0) result1^=nums[j]; else result2^=nums[j]; } result.push_back(result1); result.push_back(result2); return result; }
PS:
思路很清晰,但是写代码的是后老在细节出错,主要是两个判断条件要注意