[leetcode] 338. Counting Bits _ Algorithm Problem Solve for python

1. Problem

338. Counting Bits

Given an integer n, return an array ans of length n + 1 such that for each i (0 <= i <= n), ans[i] is the number of 1’s in the binary representation of i.

Example 1:

Input: n = 2
Output: [0,1,1]
Explanation:
0 --> 0
1 --> 1
2 --> 10

Example 2:

Input: n = 5
Output: [0,1,1,2,1,2]
Explanation:
0 --> 0
1 --> 1
2 --> 10
3 --> 11
4 --> 100
5 --> 101

Constraints:

• 1 <= s.length <= 10^5

2. Solution

I solved this problem like this.

class Solution:
    def countBits(self, n: int) -> List[int]:
        return [bin(x)[2:].count('1') for x in range(n+1)]