AI solution for JavaScript Coding Question on BFE.dev
162. find the single integer

One approach to solving this problem is by using bitwise operators. We can perform an XOR operation on each integer in the array. Since the XOR operation is associative and commutative, this means that if we XOR all the integers in the array, we will be left with the single integer that appears only once.

Here is one possible implementation:

function findSingle(arr) {
  let result = 0
  for (const num of arr) {
    result ^= num
  }
  return result
}

The time complexity of this algorithm is O(n), where n is the length of the array. We need to iterate over each integer once to perform the XOR operation. The space complexity is O(1), as we are only using a single variable to store the result.

This is already an optimal solution, as we need to look at every integer in the array at least once.