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(nsizeof(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 Solution {
public int[] countBits(int num) {
if(num == 0){
return new int[]{0};
}
int dp[] = new int[num+1];
dp[0] = 0;
dp[1] = 1;
for(int i = 2 ; i<=num; i++){
if((i & 1) == 1){
dp[i] = dp[i>>1] + 1;
}else{
dp[i] = dp[i>>1];
}
}
return dp;
}
}
