Bit Manipulation
Dynamic Programming
Description
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:
Follow up:
It is very easy to come up with a solution with a runtime of O(n log n)
. Can you do it in linear time O(n)
and possibly in a single pass?
Can you do it without using any built-in function (i.e., like __builtin_popcount
in C++)?
Solutions
Solution 1
Solution 2
GitHub