Counting Bits

<-E 338> Counting Bits

class Solution {
public:
    vector<int> countBits(int n) {
        vector<int> t(n+1, 0);
        
        for(int i = 1; i <= n; ++i)
            t[i] = t[i/2] + i%2;
        
        return t;
    }
};