题目原址：点击打开链接
题目描述：
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.我的代码：
时间复杂度应该是O（num*log(num))
class Solution { public: vector<int> countBits(int num) { vector<int> result; for(int i=0;i<=num;i++){ int k=i; int sum=0; while(k){ int j; j=k%2; k=k/2; if(j==1)sum++; } result.push_back(sum); } return result; } };