// Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and return them as an array.

// Example:

// For num = 5 you should return [0,1,1,2,1,2].

// Follow up:

// It is very easy to come up with a solution with run time O(n*sizeof(integer)). But can you do it in linear time O(n) /possibly in a single pass?

// Space complexity should be O(n).

// Can you do it like a boss? Do it without using any builtin function like __builtin_popcount in c++ or in any other language.

public class CountingBits {

public int[] countBits(int num) {

int[] bits = new int[num + 1];

bits[0] = 0;

for(int i = 1; i <= num; i++) {

bits[i] = bits[i >> 1] + (i & 1);

}

return bits;

}

}