191. Number of 1 Bits

hammingWeight.py

def hammingWeight(self, n):
    nstr = '{0:32b}'.format(n)
    count = 0
    for x in nstr:
        if x == "1":
            count += 1

    return count

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



Write a function that takes an unsigned integer and return the number of '1' bits it has (also known as the Hamming weight).
 
Example 1:
Input: 00000000000000000000000000001011
Output: 3
Explanation: The input binary string 00000000000000000000000000001011 has a total of three '1' bits.
Example 2:
Input: 00000000000000000000000010000000
Output: 1
Explanation: The input binary string 00000000000000000000000010000000 has a total of one '1' bit.
Example 3:
Input: 11111111111111111111111111111101
Output: 31
Explanation: The input binary string 11111111111111111111111111111101 has a total of thirty one '1' bits.

"""