 # Sort Integers by the Number of 1 Bits

Easy
1
42.9% Acceptance

In this lab, you will implement a function that takes an integer array as input and sorts the integers in ascending order based on the number of `1`s in their binary representation. If two or more integers have the same number of `1`s, you have to sort them in ascending order. Your task is to return the sorted array.

Example 1:

``````Input: arr = [0,1,2,3,4,5,6,7,8]
Output: [0,1,2,4,8,3,5,6,7]
Explanation:
 is the only integer with 0 bits.
[1,2,4,8] all have 1 bit.
[3,5,6] have 2 bits.
 has 3 bits.
The sorted array by bits is [0,1,2,4,8,3,5,6,7]``````

Example 2:

``````Input: arr = [1024,512,256,128,64,32,16,8,4,2,1]
Output: [1,2,4,8,16,32,64,128,256,512,1024]
Explanation:
All integers have 1 bit in the binary representation, you should just sort them in ascending order.``````

Constraints:

• `1 <= arr.length <= 500`
• `0 <= arr[i] <= 10^4`

Once you have implemented the function and passed the given test cases, you will be asked to add additional challenges and demo an evaluation script to test the user's solution. Each challenge should be properly tested upon submission.

Let's start by writing the `sortByBits` function following the given specifications and constraints. Good luck!