In this post, we are going to solve the** 191. Number of 1 Bits** problem of Leetcode. This problem **191. Number of 1 Bits** is a Leetcode **easy **level problem. Let’s see the code, **191. Number of 1 Bits****– Leetcode Solution**.

**Problem**

Write a function that takes an unsigned integer and returns the number of ‘1’ bits it has (also known as the 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. 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.
```

### E**xample 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`

.

Now, let’s see the code of **191. Number of 1 Bits** – Leetcode Solution.

**Diameter of Binary Tree – Leetcode Solution**

**191. Number of 1 Bits** – Solution in Java

**191. Number of 1 Bits**– Solution in Java

public class Solution { // you need to treat n as an unsigned value public int hammingWeight(int n) { int count =0 ; while(n != 0){ count++; n = (n & (n-1)); } return count; } }

**191. Number of 1 Bits** – Solution in C++

**C++**

**191. Number of 1 Bits**– Solution inclass Solution { public: int hammingWeight(uint32_t n) { int count =0 ; while(n != 0){ count++; n = (n & (n-1)); } return count; } };

**191. Number of 1 Bits** – Solution in Python

**Python**

**191. Number of 1 Bits**– Solution indef hammingWeight(self, n): """ :type n: int :rtype: int """ c = 0 while n: n &= n - 1 c += 1 return c

**Note:** This problem **191. Number of 1 Bits** is generated by **Leetcode **but the solution is provided by **CodingBroz**. This tutorial is only for **Educational** and **Learning** purpose.