Class Solution

java.lang.Object
g0101_0200.s0191_number_of_1_bits.Solution

public class Solution extends Object
191 - Number of 1 Bits\. Easy Write a function that takes an unsigned integer and returns the number of '1' bits it has (also known as the [Hamming weight](http://en.wikipedia.org/wiki/Hamming_weight)). **Note:** * Note that in some languages, such as Java, there is no unsigned integer type. In this case, the input will be given as a signed integer type. It should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned. * In Java, the compiler represents the signed integers using [2's complement notation](https://en.wikipedia.org/wiki/Two%27s_complement). Therefore, in **Example 3** , the input represents the signed integer. `-3`. **Example 1:** **Input:** n = 00000000000000000000000000001011 **Output:** 3 **Explanation:** The input binary string **00000000000000000000000000001011** has a total of three '1' bits. **Example 2:** **Input:** n = 00000000000000000000000010000000 **Output:** 1 **Explanation:** The input binary string **00000000000000000000000010000000** has a total of one '1' bit. **Example 3:** **Input:** n = 11111111111111111111111111111101 **Output:** 31 **Explanation:** The input binary string **11111111111111111111111111111101** has a total of thirty one '1' bits. **Constraints:** * The input must be a **binary string** of length `32`. **Follow up:** If this function is called many times, how would you optimize it?
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • hammingWeight

      public int hammingWeight(int n)