leetcode 461. Hamming Distance

14 Oct 2017 | 알고리즘 프로그래밍

문제출처

문제

The Hamming distance between two integers is the number of positions at which the corresponding bits are different.

Given two integers x and y, calculate the Hamming distance.

Note:
0 ≤ x, y < 2**31.

Example:

Input: x = 1, y = 4

Output: 2

Explanation:
1   (0 0 0 1)
4   (0 1 0 0)
       ↑   ↑

The above arrows point to positions where the corresponding bits are different.

풀이코드

def hamming_distance(x, y):
    bin_x = format(x, "032b")
    bin_y = format(y, "032b")
    result = 0
    for i in range(32):
        if bin_x[i] != bin_y[i]:
            result += 1
    return result

format() 함수를 활용 (참고)

>>> format(10, '010b')
# '0000001010'
>>> format(10, 'b')
# '1010'
>>> format(10, '#b')
# '0b1010'

다른사람풀이

비트연산자 XOR연산 활용 (XOR연산은 각 자릿수를 비교하여 다르면 1, 같으면 0)
비트연산자 참고 (codecademy)

def hamming_distance(x, y):
  return bin(x^y).count('1')