LeetCode - 461. Hamming Distance

Description

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

< 231.

Example:

Solution

除了最容易想到的暴力法，还可以用n与n-1按位与的方法

python版：

class Solution(object):
def hammingDistance(self, x, y):
"""
:type x: int
:type y: int
:rtype: int
"""
xor = x ^ y
count = 0
while (xor != 0):
xor = xor & (xor - 1)
count = count + 1

return count

cpp版：

class Solution {
public:
int hammingDistance(int x, int y)
{
int xor_diff = x ^ y;
int count = 0;
while (xor_diff != 0)
{
count++;
xor_diff = xor_diff & (xor_diff-1);
}
return count;
}
};

Reference：

http://www.cnblogs.com/grandyang/p/6201215.html