Given an array of integers, every element appears twice except for one. Find that single one. Solution:

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class Solution { public: int singleNumber(vector<int>& nums) { int A = nums[0]; for(int i = 1; i < nums.size();i++) { A = A ^ nums[i]; } return A; } }; |

C++:

return accumulate(nums.cbegin(), nums.cend(), 0, std::bit_xor());

Python:

return reduce(operator.xor, nums)