Python Challenges: Find the single element in a list where every element appears three times except for one
Python Challenges - 1: Exercise-13 with Solution
Write a Python program to find the single element in a list where every element appears three times except for one.
def single_number(arr): ones, twos = 0, 0 for x in arr: ones, twos = (ones ^ x) & ~twos, (ones & x) | (twos & ~x) assert twos == 0 return ones arr1 = [5, 3, 4, 3, 5, 5, 3] arr2 = [-1, 1, 1, -1, -1, 1, 0] print(single_number(arr1)) print(single_number(arr2))
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