dsa · easy
Counting Bits
Given a non-negative integer n, return a list ans of length n + 1 where ans[i] is how many 1 bits appear in the binary writing of i, for every i from 0 through n.
Example
n = 5. Write each integer in binary and count the ones:
0is0→ 0 ones1is1→ 1 one2is10→ 1 one3is11→ 2 ones4is100→ 1 one5is101→ 2 ones
So the answer is [0, 1, 1, 2, 1, 2].
n = 0 is only the value 0 → [0].
## Arguments - n — inclusive upper bound; return counts for 0..n
Constraints
0 <= n <= 10^5 Hidden tests include near-max size for this bound; a slower-than-intended solution TLEs.
Examples
Example 1
Input: 5 Expected: [0,1,1,2,1,2]
Example 2
Input: 0 Expected: [0]
Example 3
Input: 2 Expected: [0,1,1]