competitive/math/
black_box_mint_matrix.rs1use super::{
2 AddMulOperation, BlackBoxMatrix, BlackBoxMatrixImpl, ConvolveSteps, DotProduct,
3 FormalPowerSeries, Fps, MInt, MIntConvert, MIntDotProduct, One, Xorshift, Zero,
4};
5
6pub trait BlackBoxMIntMatrix<M>: BlackBoxMatrix<AddMulOperation<MInt<M>>>
7where
8 M: MIntDotProduct<Inner = u32>
9 + MIntConvert<u32>
10 + MIntConvert<u64>
11 + MIntConvert<usize>
12 + MIntConvert<isize>,
13{
14 fn minimal_polynomial(&self) -> Vec<MInt<M>> {
15 assert_eq!(self.shape().0, self.shape().1);
16 let n = self.shape().0;
17 let mut rng = Xorshift::new();
18 let b: Vec<MInt<M>> = (0..n).map(|_| MInt::from(rng.rand64())).collect();
19 let u: Vec<MInt<M>> = (0..n).map(|_| MInt::from(rng.rand64())).collect();
20 let a: Vec<MInt<M>> = (0..2 * n)
21 .scan(b, |b, _| {
22 let a = MInt::dot_product(b, &u);
23 *b = self.apply(b);
24 Some(a)
25 })
26 .collect();
27 let polynomial: Fps<M> = FormalPowerSeries::berlekamp_massey(&a);
28 let mut p = polynomial.data;
29 p.reverse();
30 p
31 }
32
33 fn apply_pow<C>(&self, mut b: Vec<MInt<M>>, k: usize) -> Vec<MInt<M>>
34 where
35 C: ConvolveSteps<T = Vec<MInt<M>>>,
36 {
37 assert_eq!(self.shape().0, self.shape().1);
38 assert_eq!(self.shape().1, b.len());
39 let n = self.shape().0;
40 let p = self.minimal_polynomial();
41 let polynomial: FormalPowerSeries<MInt<M>, C> = FormalPowerSeries::from_vec(p);
42 let f = polynomial.pow_mod(k);
43 let mut res = vec![MInt::zero(); n];
44 for f in f {
45 for j in 0..n {
46 res[j] += f * b[j];
47 }
48 b = self.apply(&b);
49 }
50 res
51 }
52
53 fn black_box_determinant(&self) -> MInt<M> {
54 assert_eq!(self.shape().0, self.shape().1);
55 let n = self.shape().0;
56 let mut rng = Xorshift::new();
57 let d: Vec<MInt<M>> = (0..n).map(|_| MInt::from(rng.rand64())).collect();
58 let det_d = d.iter().fold(MInt::one(), |s, x| s * x);
59 let ad: BlackBoxMatrixImpl<AddMulOperation<MInt<M>>, _> =
60 BlackBoxMatrixImpl::new(self.shape(), |v: &[MInt<M>]| {
61 let mut w = self.apply(v);
62 for (w, d) in w.iter_mut().zip(&d) {
63 *w *= d;
64 }
65 w
66 });
67 let p = ad.minimal_polynomial();
68 let det_ad = if n % 2 == 0 { p[0] } else { -p[0] };
69 det_ad / det_d
70 }
71
72 fn black_box_linear_equation(&self, mut b: Vec<MInt<M>>) -> Option<Vec<MInt<M>>> {
73 assert_eq!(self.shape().0, self.shape().1);
74 assert_eq!(self.shape().1, b.len());
75 let n = self.shape().0;
76 let p = self.minimal_polynomial();
77 if p.is_empty() || p[0].is_zero() {
78 return None;
79 }
80 let p0_inv = p[0].inv();
81 let mut x = vec![MInt::zero(); n];
82 for p in p.into_iter().skip(1) {
83 let p = -p * p0_inv;
84 for i in 0..n {
85 x[i] += p * b[i];
86 }
87 b = self.apply(&b);
88 }
89 Some(x)
90 }
91}
92
93impl<M, B> BlackBoxMIntMatrix<M> for B
94where
95 M: MIntDotProduct<Inner = u32>
96 + MIntConvert<u32>
97 + MIntConvert<u64>
98 + MIntConvert<usize>
99 + MIntConvert<isize>,
100 B: BlackBoxMatrix<AddMulOperation<MInt<M>>>,
101{
102}