Two Repeated Elements

'''
You are given an array of N+2 integer elements. All elements of the array are in range 1 to N. Also, all elements occur once except two numbers which occur twice. Find the two repeating numbers.
'''
# Python3 code to Find the
# two repeating elements
# in a given array
def printRepeating(arr, size):

    # Will hold xor
    # of all elements
    xor = arr[0]
    n = size - 2
    x = 0
    y = 0

    # Get the xor of all
    # elements in arr[]
    # and 1, 2 .. n
    for i in range(1 , size):
        xor ^= arr[i]
    for i in range(1 , n + 1):
        xor ^= i

    # Get the rightmost set
    # bit in set_bit_no
    set_bit_no = xor & ~(xor-1)

    # Now divide elements in two
    # sets by comparing rightmost
    # set bit of xor with bit at
    # same position in each element.
    for i in range(0, size):

        if(arr[i] & set_bit_no):

            # XOR of first
            # set in arr[]
            x = x ^ arr[i]
        else:

            # XOR of second
            # set in arr[]
            y = y ^ arr[i]

    for i in range(1 , n + 1):

        if(i & set_bit_no):

            # XOR of first set
            # in arr[] and
            # 1, 2, ...n
            x = x ^ i
        else:

             # XOR of second set
             # in arr[] and
             # 1, 2, ...n
            y = y ^ i

    print("The two repeating",
         "elements are", y, x)

# Driver code
arr = [4, 2, 4,
       5, 2, 3, 1]
arr_size = len(arr)
printRepeating(arr, arr_size)