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Find two unique numbers in an array with Python

Returns the two numbers that appear exactly once in a list where every other number appears twice, using XOR bit manipulation.

bit-manipulation xor arrays

Python

def find_two_odd(arr):
    """Return the two numbers that appear exactly once, while all others appear twice."""
    xor_all = 0
    for num in arr:
        xor_all ^= num

    # xor_all now equals the XOR of the two unique numbers.
    # Find a set bit (any bit where they differ).
    diff_bit = xor_all & (-xor_all)
…

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