struct Solution;
impl Solution {
fn count_bits(num: i32) -> Vec<i32> {
let n = num as usize;
let mut res = vec![];
for i in 0..=n {
res.push(i.count_ones() as i32);
}
res
}
}
#[test]
fn test() {
let num = 2;
let res = vec![0, 1, 1];
assert_eq!(Solution::count_bits(num), res);
}