995，时间复杂度降不下来

#include<iostream>
using namespace std;
long long l, r;
long long sum = 0;
int cnt(int x,int c)
{
    if (x & 1) c++;
    if (x == 0)return c;
    else return cnt(x / 2, c);
}
int main()
{
    cin >> l >> r;
    for (long long i = l; i <= r; i++)
    {
        long long t = i, s = 0;
        if (cnt(t, s) % 2)
            sum += i;
    }
    cout << sum << endl;
    return 0;
}