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)