bitset-fixed

Bitset for DP.

Example

Example for AGC20-C

```rust use bitset_fixed::BitSet; use rand::prelude::*;

fn main() { let mut rng = StdRng::seedfromu64(114514);

let n: Vec<usize> = (0..25).map(|_| rng.next_u32() as usize % 2000).collect();
let sum = n.iter().sum::<usize>();

let mut bitset = BitSet::new(sum + 1);
bitset.set(0, true);

for &x in &n {
    bitset |= &(&bitset << x);
}

let ans = ((sum + 1) / 2..).find(|&i| bitset[i]).unwrap();

println!("N = {:?}\nAnswer = {}", n, ans);

} ```