338. 比特位计数 Java版

class Solution {
    public int[] countBits(int n) {

        int[] res = new int[n + 1];

        for(int i=0; i<=n; i++){
            if(i%2 == 0)
                res[i] = res[i/2];

            else
                res[i] = res[i/2] + 1;
        }

        return res;
    }
}