[LeetCode] 191. Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).
For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

Thought process:
Use Integer built-in method.

Solution:

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public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        return Integer.bitCount(n);
    }
}

Time complexity: O(n) where n is the number of bits of n.
Location: Philadelphia, PA, USA

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