Submission #41481462
Source Code Expand
use modint::ModInt1000000007 as ModInt;
use proconio::input;
fn main() {
input! {
n: usize,
m: usize,
a: [usize; m],
}
let mut ok = vec![true; n + 1];
for a_i in a {
ok[a_i] = false;
}
let mut dp = vec![ModInt::new(0); n + 1];
dp[0] = ModInt::new(1);
for i in 0..=n {
for j in i + 1..=i + 2 {
if j <= n && ok[j] {
dp[j] = dp[j] + dp[i];
}
}
}
let ans = dp[n];
println!("{}", ans);
}
//https://github.com/rust-lang-ja/ac-library-rs
pub mod internal_math {
// remove this after dependencies has been added
#![allow(dead_code)]
use std::mem::swap;
/// # Arguments
/// * `m` `1 <= m`
///
/// # Returns
/// x mod m
/* const */
pub(crate) fn safe_mod(mut x: i64, m: i64) -> i64 {
x %= m;
if x < 0 {
x += m;
}
x
}
/// Fast modular by barrett reduction
/// Reference: https://en.wikipedia.org/wiki/Barrett_reduction
/// NOTE: reconsider after Ice Lake
pub(crate) struct Barrett {
pub(crate) _m: u32,
pub(crate) im: u64,
}
impl Barrett {
/// # Arguments
/// * `m` `1 <= m`
/// (Note: `m <= 2^31` should also hold, which is undocumented in the original library.
/// See the [pull reqeust commment](https://github.com/rust-lang-ja/ac-library-rs/pull/3#discussion_r484661007)
/// for more details.)
pub(crate) fn new(m: u32) -> Barrett {
Barrett {
_m: m,
im: (-1i64 as u64 / m as u64).wrapping_add(1),
}
}
/// # Returns
/// `m`
pub(crate) fn umod(&self) -> u32 {
self._m
}
/// # Parameters
/// * `a` `0 <= a < m`
/// * `b` `0 <= b < m`
///
/// # Returns
/// a * b % m
#[allow(clippy::many_single_char_names)]
pub(crate) fn mul(&self, a: u32, b: u32) -> u32 {
mul_mod(a, b, self._m, self.im)
}
}
/// Calculates `a * b % m`.
///
/// * `a` `0 <= a < m`
/// * `b` `0 <= b < m`
/// * `m` `1 <= m <= 2^31`
/// * `im` = ceil(2^64 / `m`)
#[allow(clippy::many_single_char_names)]
pub(crate) fn mul_mod(a: u32, b: u32, m: u32, im: u64) -> u32 {
// [1] m = 1
// a = b = im = 0, so okay
// [2] m >= 2
// im = ceil(2^64 / m)
// -> im * m = 2^64 + r (0 <= r < m)
// let z = a*b = c*m + d (0 <= c, d < m)
// a*b * im = (c*m + d) * im = c*(im*m) + d*im = c*2^64 + c*r + d*im
// c*r + d*im < m * m + m * im < m * m + 2^64 + m <= 2^64 + m * (m + 1) < 2^64 * 2
// ((ab * im) >> 64) == c or c + 1
let mut z = a as u64;
z *= b as u64;
let x = (((z as u128) * (im as u128)) >> 64) as u64;
let mut v = z.wrapping_sub(x.wrapping_mul(m as u64)) as u32;
if m <= v {
v = v.wrapping_add(m);
}
v
}
/// # Parameters
/// * `n` `0 <= n`
/// * `m` `1 <= m`
///
/// # Returns
/// `(x ** n) % m`
/* const */
#[allow(clippy::many_single_char_names)]
pub(crate) fn pow_mod(x: i64, mut n: i64, m: i32) -> i64 {
if m == 1 {
return 0;
}
let _m = m as u32;
let mut r: u64 = 1;
let mut y: u64 = safe_mod(x, m as i64) as u64;
while n != 0 {
if (n & 1) > 0 {
r = (r * y) % (_m as u64);
}
y = (y * y) % (_m as u64);
n >>= 1;
}
r as i64
}
/// Reference:
/// M. Forisek and J. Jancina,
/// Fast Primality Testing for Integers That Fit into a Machine Word
///
/// # Parameters
/// * `n` `0 <= n`
/* const */
pub(crate) fn is_prime(n: i32) -> bool {
let n = n as i64;
match n {
_ if n <= 1 => return false,
2 | 7 | 61 => return true,
_ if n % 2 == 0 => return false,
_ => {}
}
let mut d = n - 1;
while d % 2 == 0 {
d /= 2;
}
for &a in &[2, 7, 61] {
let mut t = d;
let mut y = pow_mod(a, t, n as i32);
while t != n - 1 && y != 1 && y != n - 1 {
y = y * y % n;
t <<= 1;
}
if y != n - 1 && t % 2 == 0 {
return false;
}
}
true
}
// omitted
// template <int n> constexpr bool is_prime = is_prime_constexpr(n);
/// # Parameters
/// * `b` `1 <= b`
///
/// # Returns
/// (g, x) s.t. g = gcd(a, b), xa = g (mod b), 0 <= x < b/g
/* const */
#[allow(clippy::many_single_char_names)]
pub(crate) fn inv_gcd(a: i64, b: i64) -> (i64, i64) {
let a = safe_mod(a, b);
if a == 0 {
return (b, 0);
}
// Contracts:
// [1] s - m0 * a = 0 (mod b)
// [2] t - m1 * a = 0 (mod b)
// [3] s * |m1| + t * |m0| <= b
let mut s = b;
let mut t = a;
let mut m0 = 0;
let mut m1 = 1;
while t != 0 {
let u = s / t;
s -= t * u;
m0 -= m1 * u; // |m1 * u| <= |m1| * s <= b
// [3]:
// (s - t * u) * |m1| + t * |m0 - m1 * u|
// <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u)
// = s * |m1| + t * |m0| <= b
swap(&mut s, &mut t);
swap(&mut m0, &mut m1);
}
// by [3]: |m0| <= b/g
// by g != b: |m0| < b/g
if m0 < 0 {
m0 += b / s;
}
(s, m0)
}
/// Compile time (currently not) primitive root
/// @param m must be prime
/// @return primitive root (and minimum in now)
/* const */
pub(crate) fn primitive_root(m: i32) -> i32 {
match m {
2 => return 1,
167_772_161 => return 3,
469_762_049 => return 3,
754_974_721 => return 11,
998_244_353 => return 3,
_ => {}
}
let mut divs = [0; 20];
divs[0] = 2;
let mut cnt = 1;
let mut x = (m - 1) / 2;
while x % 2 == 0 {
x /= 2;
}
for i in (3..std::i32::MAX).step_by(2) {
if i as i64 * i as i64 > x as i64 {
break;
}
if x % i == 0 {
divs[cnt] = i;
cnt += 1;
while x % i == 0 {
x /= i;
}
}
}
if x > 1 {
divs[cnt] = x;
cnt += 1;
}
let mut g = 2;
loop {
if (0..cnt).all(|i| pow_mod(g, ((m - 1) / divs[i]) as i64, m) != 1) {
break g as i32;
}
g += 1;
}
}
// omitted
// template <int m> constexpr int primitive_root = primitive_root_constexpr(m);
#[cfg(test)]
mod tests {
#![allow(clippy::unreadable_literal)]
#![allow(clippy::cognitive_complexity)]
use crate::internal_math::{inv_gcd, is_prime, pow_mod, primitive_root, safe_mod, Barrett};
use std::collections::HashSet;
#[test]
fn test_safe_mod() {
assert_eq!(safe_mod(0, 3), 0);
assert_eq!(safe_mod(1, 3), 1);
assert_eq!(safe_mod(2, 3), 2);
assert_eq!(safe_mod(3, 3), 0);
assert_eq!(safe_mod(4, 3), 1);
assert_eq!(safe_mod(5, 3), 2);
assert_eq!(safe_mod(73, 11), 7);
assert_eq!(safe_mod(2306249155046129918, 6620319213327), 1374210749525);
assert_eq!(safe_mod(-1, 3), 2);
assert_eq!(safe_mod(-2, 3), 1);
assert_eq!(safe_mod(-3, 3), 0);
assert_eq!(safe_mod(-4, 3), 2);
assert_eq!(safe_mod(-5, 3), 1);
assert_eq!(safe_mod(-7170500492396019511, 777567337), 333221848);
}
#[test]
fn test_barrett() {
let b = Barrett::new(7);
assert_eq!(b.umod(), 7);
assert_eq!(b.mul(2, 3), 6);
assert_eq!(b.mul(4, 6), 3);
assert_eq!(b.mul(5, 0), 0);
let b = Barrett::new(998244353);
assert_eq!(b.umod(), 998244353);
assert_eq!(b.mul(2, 3), 6);
assert_eq!(b.mul(3141592, 653589), 919583920);
assert_eq!(b.mul(323846264, 338327950), 568012980);
// make `z - x * self._m as u64` overflow.
// Thanks @koba-e964 (at https://github.com/rust-lang-ja/ac-library-rs/pull/3#discussion_r484932161)
let b = Barrett::new(2147483647);
assert_eq!(b.umod(), 2147483647);
assert_eq!(b.mul(1073741824, 2147483645), 2147483646);
}
#[test]
fn test_pow_mod() {
assert_eq!(pow_mod(0, 0, 1), 0);
assert_eq!(pow_mod(0, 0, 3), 1);
assert_eq!(pow_mod(0, 0, 723), 1);
assert_eq!(pow_mod(0, 0, 998244353), 1);
assert_eq!(pow_mod(0, 0, i32::max_value()), 1);
assert_eq!(pow_mod(0, 1, 1), 0);
assert_eq!(pow_mod(0, 1, 3), 0);
assert_eq!(pow_mod(0, 1, 723), 0);
assert_eq!(pow_mod(0, 1, 998244353), 0);
assert_eq!(pow_mod(0, 1, i32::max_value()), 0);
assert_eq!(pow_mod(0, i64::max_value(), 1), 0);
assert_eq!(pow_mod(0, i64::max_value(), 3), 0);
assert_eq!(pow_mod(0, i64::max_value(), 723), 0);
assert_eq!(pow_mod(0, i64::max_value(), 998244353), 0);
assert_eq!(pow_mod(0, i64::max_value(), i32::max_value()), 0);
assert_eq!(pow_mod(1, 0, 1), 0);
assert_eq!(pow_mod(1, 0, 3), 1);
assert_eq!(pow_mod(1, 0, 723), 1);
assert_eq!(pow_mod(1, 0, 998244353), 1);
assert_eq!(pow_mod(1, 0, i32::max_value()), 1);
assert_eq!(pow_mod(1, 1, 1), 0);
assert_eq!(pow_mod(1, 1, 3), 1);
assert_eq!(pow_mod(1, 1, 723), 1);
assert_eq!(pow_mod(1, 1, 998244353), 1);
assert_eq!(pow_mod(1, 1, i32::max_value()), 1);
assert_eq!(pow_mod(1, i64::max_value(), 1), 0);
assert_eq!(pow_mod(1, i64::max_value(), 3), 1);
assert_eq!(pow_mod(1, i64::max_value(), 723), 1);
assert_eq!(pow_mod(1, i64::max_value(), 998244353), 1);
assert_eq!(pow_mod(1, i64::max_value(), i32::max_value()), 1);
assert_eq!(pow_mod(i64::max_value(), 0, 1), 0);
assert_eq!(pow_mod(i64::max_value(), 0, 3), 1);
assert_eq!(pow_mod(i64::max_value(), 0, 723), 1);
assert_eq!(pow_mod(i64::max_value(), 0, 998244353), 1);
assert_eq!(pow_mod(i64::max_value(), 0, i32::max_value()), 1);
assert_eq!(pow_mod(i64::max_value(), i64::max_value(), 1), 0);
assert_eq!(pow_mod(i64::max_value(), i64::max_value(), 3), 1);
assert_eq!(pow_mod(i64::max_value(), i64::max_value(), 723), 640);
assert_eq!(
pow_mod(i64::max_value(), i64::max_value(), 998244353),
683296792
);
assert_eq!(
pow_mod(i64::max_value(), i64::max_value(), i32::max_value()),
1
);
assert_eq!(pow_mod(2, 3, 1_000_000_007), 8);
assert_eq!(pow_mod(5, 7, 1_000_000_007), 78125);
assert_eq!(pow_mod(123, 456, 1_000_000_007), 565291922);
}
#[test]
fn test_is_prime() {
assert!(!is_prime(0));
assert!(!is_prime(1));
assert!(is_prime(2));
assert!(is_prime(3));
assert!(!is_prime(4));
assert!(is_prime(5));
assert!(!is_prime(6));
assert!(is_prime(7));
assert!(!is_prime(8));
assert!(!is_prime(9));
// assert!(is_prime(57));
assert!(!is_prime(57));
assert!(!is_prime(58));
assert!(is_prime(59));
assert!(!is_prime(60));
assert!(is_prime(61));
assert!(!is_prime(62));
assert!(!is_prime(701928443));
assert!(is_prime(998244353));
assert!(!is_prime(1_000_000_000));
assert!(is_prime(1_000_000_007));
assert!(is_prime(i32::max_value()));
}
#[test]
fn test_is_prime_sieve() {
let n = 1_000_000;
let mut prime = vec![true; n];
prime[0] = false;
prime[1] = false;
for i in 0..n {
assert_eq!(prime[i], is_prime(i as i32));
if prime[i] {
for j in (2 * i..n).step_by(i) {
prime[j] = false;
}
}
}
}
#[test]
fn test_inv_gcd() {
for &(a, b, g) in &[
(0, 1, 1),
(0, 4, 4),
(0, 7, 7),
(2, 3, 1),
(-2, 3, 1),
(4, 6, 2),
(-4, 6, 2),
(13, 23, 1),
(57, 81, 3),
(12345, 67890, 15),
(-3141592 * 6535, 3141592 * 8979, 3141592),
(i64::max_value(), i64::max_value(), i64::max_value()),
(i64::min_value(), i64::max_value(), 1),
] {
let (g_, x) = inv_gcd(a, b);
assert_eq!(g, g_);
let b_ = b as i128;
assert_eq!(((x as i128 * a as i128) % b_ + b_) % b_, g as i128 % b_);
}
}
#[test]
fn test_primitive_root() {
for &p in &[
2,
3,
5,
7,
233,
200003,
998244353,
1_000_000_007,
i32::max_value(),
] {
assert!(is_prime(p));
let g = primitive_root(p);
if p != 2 {
assert_ne!(g, 1);
}
let q = p - 1;
for i in (2..i32::max_value()).take_while(|i| i * i <= q) {
if q % i != 0 {
break;
}
for &r in &[i, q / i] {
assert_ne!(pow_mod(g as i64, r as i64, p), 1);
}
}
assert_eq!(pow_mod(g as i64, q as i64, p), 1);
if p < 1_000_000 {
assert_eq!(
(0..p - 1)
.scan(1, |i, _| {
*i = *i * g % p;
Some(*i)
})
.collect::<HashSet<_>>()
.len() as i32,
p - 1
);
}
}
}
}
}
pub mod modint {
//! Structs that treat the modular arithmetic.
//!
//! For most of the problems, It is sufficient to use [`ModInt1000000007`] or [`ModInt998244353`], which can be used as follows.
//!
//! ```
//! use ac_library_rs::ModInt1000000007 as Mint; // rename to whatever you want
//! use proconio::{input, source::once::OnceSource};
//!
//! input! {
//! from OnceSource::from("1000000006 2\n"),
//! a: Mint,
//! b: Mint,
//! }
//!
//! println!("{}", a + b); // `1`
//! ```
//!
//! If the modulus is not fixed, you can use [`ModInt`] as follows.
//!
//! ```
//! use ac_library_rs::ModInt as Mint; // rename to whatever you want
//! use proconio::{input, source::once::OnceSource};
//!
//! input! {
//! from OnceSource::from("3 3 7\n"),
//! a: u32,
//! b: u32,
//! m: u32,
//! }
//!
//! Mint::set_modulus(m);
//! let a = Mint::new(a);
//! let b = Mint::new(b);
//!
//! println!("{}", a * b); // `2`
//! ```
//!
//! # Major changes from the original ACL
//!
//! - Converted the struct names to PascalCase.
//! - Renamed `mod` → `modulus`.
//! - Moduli are `u32`, not `i32`.
//! - Each `Id` does not have a identifier number. Instead, they explicitly own `&'static LocalKey<RefCell<Barrett>>`.
//! - The type of the argument of `pow` is `u64`, not `i64`.
//! - Modints implement `FromStr` and `Display`. Modints in the original ACL don't have `operator<<` or `operator>>`.
//!
//! [`ModInt1000000007`]: ./type.ModInt1000000007.html
//! [`ModInt998244353`]: ./type.ModInt998244353.html
//! [`ModInt`]: ./type.ModInt.html
use crate::internal_math;
use std::{
cell::RefCell,
convert::{Infallible, TryInto as _},
fmt,
hash::{Hash, Hasher},
iter::{Product, Sum},
marker::PhantomData,
ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Sub, SubAssign},
str::FromStr,
sync::atomic::{self, AtomicU32, AtomicU64},
thread::LocalKey,
};
pub type ModInt1000000007 = StaticModInt<Mod1000000007>;
pub type ModInt998244353 = StaticModInt<Mod998244353>;
pub type ModInt = DynamicModInt<DefaultId>;
/// Represents _ℤ/mℤ_ where _m_ is a constant value.
///
/// Corresponds to `atcoder::static_modint` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::ModInt1000000007 as Mint;
/// use proconio::{input, source::once::OnceSource};
///
/// input! {
/// from OnceSource::from("1000000006 2\n"),
/// a: Mint,
/// b: Mint,
/// }
///
/// println!("{}", a + b); // `1`
/// ```
#[derive(Copy, Clone, Eq, PartialEq)]
#[repr(transparent)]
pub struct StaticModInt<M> {
val: u32,
phantom: PhantomData<fn() -> M>,
}
impl<M: Modulus> StaticModInt<M> {
/// Returns the modulus, which is [`<M as Modulus>::VALUE`].
///
/// Corresponds to `atcoder::static_modint::mod` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::ModInt1000000007 as Mint;
///
/// assert_eq!(1_000_000_007, Mint::modulus());
/// ```
///
/// [`<M as Modulus>::VALUE`]: ../trait.Modulus.html#associatedconstant.VALUE
#[inline(always)]
pub fn modulus() -> u32 {
M::VALUE
}
/// Creates a new `StaticModInt`.
///
/// Takes [any primitive integer].
///
/// Corresponds to the constructor of `atcoder::static_modint` in the original ACL.
///
/// [any primitive integer]: ../trait.RemEuclidU32.html
#[inline]
pub fn new<T: RemEuclidU32>(val: T) -> Self {
Self::raw(val.rem_euclid_u32(M::VALUE))
}
/// Constructs a `StaticModInt` from a `val < Self::modulus()` without checking it.
///
/// Corresponds to `atcoder::static_modint::raw` in the original ACL.
///
/// # Constraints
///
/// - `val` is less than `Self::modulus()`
///
/// See [`ModIntBase::raw`] for more more details.
///
/// [`ModIntBase::raw`]: ./trait.ModIntBase.html#tymethod.raw
#[inline]
pub fn raw(val: u32) -> Self {
Self {
val,
phantom: PhantomData,
}
}
/// Retruns the representative.
///
/// Corresponds to `atcoder::static_modint::val` in the original ACL.
#[inline]
pub fn val(self) -> u32 {
self.val
}
/// Returns `self` to the power of `n`.
///
/// Corresponds to `atcoder::static_modint::pow` in the original ACL.
#[inline]
pub fn pow(self, n: u64) -> Self {
<Self as ModIntBase>::pow(self, n)
}
/// Retruns the multiplicative inverse of `self`.
///
/// Corresponds to `atcoder::static_modint::inv` in the original ACL.
///
/// # Panics
///
/// Panics if the multiplicative inverse does not exist.
#[inline]
pub fn inv(self) -> Self {
if M::HINT_VALUE_IS_PRIME {
if self.val() == 0 {
panic!("attempt to divide by zero");
}
debug_assert!(
internal_math::is_prime(M::VALUE.try_into().unwrap()),
"{} is not a prime number",
M::VALUE,
);
self.pow((M::VALUE - 2).into())
} else {
Self::inv_for_non_prime_modulus(self)
}
}
}
/// These methods are implemented for the struct.
/// You don't need to `use` `ModIntBase` to call methods of `StaticModInt`.
impl<M: Modulus> ModIntBase for StaticModInt<M> {
#[inline(always)]
fn modulus() -> u32 {
Self::modulus()
}
#[inline]
fn raw(val: u32) -> Self {
Self::raw(val)
}
#[inline]
fn val(self) -> u32 {
self.val()
}
#[inline]
fn inv(self) -> Self {
self.inv()
}
}
/// Represents a modulus.
///
/// # Example
///
/// ```
/// macro_rules! modulus {
/// ($($name:ident($value:expr, $is_prime:expr)),*) => {
/// $(
/// #[derive(Copy, Clone, Eq, PartialEq)]
/// enum $name {}
///
/// impl ac_library_rs::modint::Modulus for $name {
/// const VALUE: u32 = $value;
/// const HINT_VALUE_IS_PRIME: bool = $is_prime;
///
/// fn butterfly_cache() -> &'static ::std::thread::LocalKey<::std::cell::RefCell<::std::option::Option<ac_library_rs::modint::ButterflyCache<Self>>>> {
/// thread_local! {
/// static BUTTERFLY_CACHE: ::std::cell::RefCell<::std::option::Option<ac_library_rs::modint::ButterflyCache<$name>>> = ::std::default::Default::default();
/// }
/// &BUTTERFLY_CACHE
/// }
/// }
/// )*
/// };
/// }
///
/// use ac_library_rs::StaticModInt;
///
/// modulus!(Mod101(101, true), Mod103(103, true));
///
/// type Z101 = StaticModInt<Mod101>;
/// type Z103 = StaticModInt<Mod103>;
///
/// assert_eq!(Z101::new(101), Z101::new(0));
/// assert_eq!(Z103::new(103), Z103::new(0));
/// ```
pub trait Modulus: 'static + Copy + Eq {
const VALUE: u32;
const HINT_VALUE_IS_PRIME: bool;
fn butterfly_cache() -> &'static LocalKey<RefCell<Option<ButterflyCache<Self>>>>;
}
/// Represents _1000000007_.
#[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Debug)]
pub enum Mod1000000007 {}
impl Modulus for Mod1000000007 {
const VALUE: u32 = 1_000_000_007;
const HINT_VALUE_IS_PRIME: bool = true;
fn butterfly_cache() -> &'static LocalKey<RefCell<Option<ButterflyCache<Self>>>> {
thread_local! {
static BUTTERFLY_CACHE: RefCell<Option<ButterflyCache<Mod1000000007>>> = RefCell::default();
}
&BUTTERFLY_CACHE
}
}
/// Represents _998244353_.
#[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Debug)]
pub enum Mod998244353 {}
impl Modulus for Mod998244353 {
const VALUE: u32 = 998_244_353;
const HINT_VALUE_IS_PRIME: bool = true;
fn butterfly_cache() -> &'static LocalKey<RefCell<Option<ButterflyCache<Self>>>> {
thread_local! {
static BUTTERFLY_CACHE: RefCell<Option<ButterflyCache<Mod998244353>>> = RefCell::default();
}
&BUTTERFLY_CACHE
}
}
/// Cache for butterfly operations.
pub struct ButterflyCache<M> {
pub(crate) sum_e: Vec<StaticModInt<M>>,
pub(crate) sum_ie: Vec<StaticModInt<M>>,
}
/// Represents _ℤ/mℤ_ where _m_ is a dynamic value.
///
/// Corresponds to `atcoder::dynamic_modint` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::ModInt as Mint;
/// use proconio::{input, source::once::OnceSource};
///
/// input! {
/// from OnceSource::from("3 3 7\n"),
/// a: u32,
/// b: u32,
/// m: u32,
/// }
///
/// Mint::set_modulus(m);
/// let a = Mint::new(a);
/// let b = Mint::new(b);
///
/// println!("{}", a * b); // `2`
/// ```
#[derive(Copy, Clone, Eq, PartialEq)]
#[repr(transparent)]
pub struct DynamicModInt<I> {
val: u32,
phantom: PhantomData<fn() -> I>,
}
impl<I: Id> DynamicModInt<I> {
/// Returns the modulus.
///
/// Corresponds to `atcoder::dynamic_modint::mod` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::ModInt as Mint;
///
/// assert_eq!(998_244_353, Mint::modulus()); // default modulus
/// ```
#[inline]
pub fn modulus() -> u32 {
I::companion_barrett().umod()
}
/// Sets a modulus.
///
/// Corresponds to `atcoder::dynamic_modint::set_mod` in the original ACL.
///
/// # Constraints
///
/// - This function must be called earlier than any other operation of `Self`.
///
/// # Example
///
/// ```
/// use ac_library_rs::ModInt as Mint;
///
/// Mint::set_modulus(7);
/// assert_eq!(7, Mint::modulus());
/// ```
#[inline]
pub fn set_modulus(modulus: u32) {
if modulus == 0 {
panic!("the modulus must not be 0");
}
I::companion_barrett().update(modulus);
}
/// Creates a new `DynamicModInt`.
///
/// Takes [any primitive integer].
///
/// Corresponds to the constructor of `atcoder::dynamic_modint` in the original ACL.
///
/// [any primitive integer]: ../trait.RemEuclidU32.html
#[inline]
pub fn new<T: RemEuclidU32>(val: T) -> Self {
<Self as ModIntBase>::new(val)
}
/// Constructs a `DynamicModInt` from a `val < Self::modulus()` without checking it.
///
/// Corresponds to `atcoder::dynamic_modint::raw` in the original ACL.
///
/// # Constraints
///
/// - `val` is less than `Self::modulus()`
///
/// See [`ModIntBase::raw`] for more more details.
///
/// [`ModIntBase::raw`]: ./trait.ModIntBase.html#tymethod.raw
#[inline]
pub fn raw(val: u32) -> Self {
Self {
val,
phantom: PhantomData,
}
}
/// Retruns the representative.
///
/// Corresponds to `atcoder::static_modint::val` in the original ACL.
#[inline]
pub fn val(self) -> u32 {
self.val
}
/// Returns `self` to the power of `n`.
///
/// Corresponds to `atcoder::dynamic_modint::pow` in the original ACL.
#[inline]
pub fn pow(self, n: u64) -> Self {
<Self as ModIntBase>::pow(self, n)
}
/// Retruns the multiplicative inverse of `self`.
///
/// Corresponds to `atcoder::dynamic_modint::inv` in the original ACL.
///
/// # Panics
///
/// Panics if the multiplicative inverse does not exist.
#[inline]
pub fn inv(self) -> Self {
Self::inv_for_non_prime_modulus(self)
}
}
/// These methods are implemented for the struct.
/// You don't need to `use` `ModIntBase` to call methods of `DynamicModInt`.
impl<I: Id> ModIntBase for DynamicModInt<I> {
#[inline]
fn modulus() -> u32 {
Self::modulus()
}
#[inline]
fn raw(val: u32) -> Self {
Self::raw(val)
}
#[inline]
fn val(self) -> u32 {
self.val()
}
#[inline]
fn inv(self) -> Self {
self.inv()
}
}
pub trait Id: 'static + Copy + Eq {
fn companion_barrett() -> &'static Barrett;
}
#[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Debug)]
pub enum DefaultId {}
impl Id for DefaultId {
fn companion_barrett() -> &'static Barrett {
static BARRETT: Barrett = Barrett::default();
&BARRETT
}
}
/// Pair of _m_ and _ceil(2⁶⁴/m)_.
pub struct Barrett {
m: AtomicU32,
im: AtomicU64,
}
impl Barrett {
/// Creates a new `Barrett`.
#[inline]
pub const fn new(m: u32) -> Self {
Self {
m: AtomicU32::new(m),
im: AtomicU64::new((-1i64 as u64 / m as u64).wrapping_add(1)),
}
}
#[inline]
const fn default() -> Self {
Self::new(998_244_353)
}
#[inline]
fn update(&self, m: u32) {
let im = (-1i64 as u64 / m as u64).wrapping_add(1);
self.m.store(m, atomic::Ordering::SeqCst);
self.im.store(im, atomic::Ordering::SeqCst);
}
#[inline]
fn umod(&self) -> u32 {
self.m.load(atomic::Ordering::SeqCst)
}
#[inline]
fn mul(&self, a: u32, b: u32) -> u32 {
let m = self.m.load(atomic::Ordering::SeqCst);
let im = self.im.load(atomic::Ordering::SeqCst);
internal_math::mul_mod(a, b, m, im)
}
}
impl Default for Barrett {
#[inline]
fn default() -> Self {
Self::default()
}
}
/// A trait for [`StaticModInt`] and [`DynamicModInt`].
///
/// Corresponds to `atcoder::internal::modint_base` in the original ACL.
///
/// [`StaticModInt`]: ../struct.StaticModInt.html
/// [`DynamicModInt`]: ../struct.DynamicModInt.html
pub trait ModIntBase:
Default
+ FromStr
+ From<i8>
+ From<i16>
+ From<i32>
+ From<i64>
+ From<i128>
+ From<isize>
+ From<u8>
+ From<u16>
+ From<u32>
+ From<u64>
+ From<u128>
+ From<usize>
+ Copy
+ Eq
+ Hash
+ fmt::Display
+ fmt::Debug
+ Neg<Output = Self>
+ Add<Output = Self>
+ Sub<Output = Self>
+ Mul<Output = Self>
+ Div<Output = Self>
+ AddAssign
+ SubAssign
+ MulAssign
+ DivAssign
{
/// Returns the modulus.
///
/// Corresponds to `atcoder::static_modint::mod` and `atcoder::dynamic_modint::mod` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>() {
/// let _: u32 = Z::modulus();
/// }
/// ```
fn modulus() -> u32;
/// Constructs a `Self` from a `val < Self::modulus()` without checking it.
///
/// Corresponds to `atcoder::static_modint::raw` and `atcoder::dynamic_modint::raw` in the original ACL.
///
/// # Constraints
///
/// - `val` is less than `Self::modulus()`
///
/// **Note that all operations assume that inner values are smaller than the modulus.**
/// If `val` is greater than or equal to `Self::modulus()`, the behaviors are not defined.
///
/// ```should_panic
/// use ac_library_rs::ModInt1000000007 as Mint;
///
/// let x = Mint::raw(1_000_000_007);
/// let y = x + x;
/// assert_eq!(0, y.val());
/// ```
///
/// ```text
/// thread 'main' panicked at 'assertion failed: `(left == right)`
/// left: `0`,
/// right: `1000000007`', src/modint.rs:8:1
/// note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
/// ```
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>() -> Z {
/// debug_assert!(Z::modulus() >= 100);
///
/// let mut acc = Z::new(0);
/// for i in 0..100 {
/// if i % 3 == 0 {
/// // I know `i` is smaller than the modulus!
/// acc += Z::raw(i);
/// }
/// }
/// acc
/// }
/// ```
fn raw(val: u32) -> Self;
/// Retruns the representative.
///
/// Corresponds to `atcoder::static_modint::val` and `atcoder::dynamic_modint::val` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>(x: Z) {
/// let _: u32 = x.val();
/// }
/// ```
fn val(self) -> u32;
/// Retruns the multiplicative inverse of `self`.
///
/// Corresponds to `atcoder::static_modint::inv` and `atcoder::dynamic_modint::inv` in the original ACL.
///
/// # Panics
///
/// Panics if the multiplicative inverse does not exist.
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>(x: Z) {
/// let _: Z = x.inv();
/// }
/// ```
fn inv(self) -> Self;
/// Creates a new `Self`.
///
/// Takes [any primitive integer].
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>() {
/// let _ = Z::new(1u32);
/// let _ = Z::new(1usize);
/// let _ = Z::new(-1i64);
/// }
/// ```
///
/// [any primitive integer]: ../trait.RemEuclidU32.html
#[inline]
fn new<T: RemEuclidU32>(val: T) -> Self {
Self::raw(val.rem_euclid_u32(Self::modulus()))
}
/// Returns `self` to the power of `n`.
///
/// Corresponds to `atcoder::static_modint::pow` and `atcoder::dynamic_modint::pow` in the original ACL.
///
/// # Example
///
/// ```
/// use ac_library_rs::modint::ModIntBase;
///
/// fn f<Z: ModIntBase>() {
/// let _: Z = Z::new(2).pow(3);
/// }
/// ```
#[inline]
fn pow(self, mut n: u64) -> Self {
let mut x = self;
let mut r = Self::raw(1);
while n > 0 {
if n & 1 == 1 {
r *= x;
}
x *= x;
n >>= 1;
}
r
}
}
/// A trait for `{StaticModInt, DynamicModInt, ModIntBase}::new`.
pub trait RemEuclidU32 {
/// Calculates `self` _mod_ `modulus` losslessly.
fn rem_euclid_u32(self, modulus: u32) -> u32;
}
macro_rules! impl_rem_euclid_u32_for_small_signed {
($($ty:tt),*) => {
$(
impl RemEuclidU32 for $ty {
#[inline]
fn rem_euclid_u32(self, modulus: u32) -> u32 {
(self as i64).rem_euclid(i64::from(modulus)) as _
}
}
)*
}
}
impl_rem_euclid_u32_for_small_signed!(i8, i16, i32, i64, isize);
impl RemEuclidU32 for i128 {
#[inline]
fn rem_euclid_u32(self, modulus: u32) -> u32 {
self.rem_euclid(i128::from(modulus)) as _
}
}
macro_rules! impl_rem_euclid_u32_for_small_unsigned {
($($ty:tt),*) => {
$(
impl RemEuclidU32 for $ty {
#[inline]
fn rem_euclid_u32(self, modulus: u32) -> u32 {
self as u32 % modulus
}
}
)*
}
}
macro_rules! impl_rem_euclid_u32_for_large_unsigned {
($($ty:tt),*) => {
$(
impl RemEuclidU32 for $ty {
#[inline]
fn rem_euclid_u32(self, modulus: u32) -> u32 {
(self % (modulus as $ty)) as _
}
}
)*
}
}
impl_rem_euclid_u32_for_small_unsigned!(u8, u16, u32);
impl_rem_euclid_u32_for_large_unsigned!(u64, u128);
#[cfg(target_pointer_width = "32")]
impl_rem_euclid_u32_for_small_unsigned!(usize);
#[cfg(target_pointer_width = "64")]
impl_rem_euclid_u32_for_large_unsigned!(usize);
trait InternalImplementations: ModIntBase {
#[inline]
fn inv_for_non_prime_modulus(this: Self) -> Self {
let (gcd, x) = internal_math::inv_gcd(this.val().into(), Self::modulus().into());
if gcd != 1 {
panic!("the multiplicative inverse does not exist");
}
Self::new(x)
}
#[inline]
fn default_impl() -> Self {
Self::raw(0)
}
#[inline]
fn from_str_impl(s: &str) -> Result<Self, Infallible> {
Ok(s.parse::<i64>()
.map(Self::new)
.unwrap_or_else(|_| todo!("parsing as an arbitrary precision integer?")))
}
#[inline]
fn hash_impl(this: &Self, state: &mut impl Hasher) {
this.val().hash(state)
}
#[inline]
fn display_impl(this: &Self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&this.val(), f)
}
#[inline]
fn debug_impl(this: &Self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&this.val(), f)
}
#[inline]
fn neg_impl(this: Self) -> Self {
Self::sub_impl(Self::raw(0), this)
}
#[inline]
fn add_impl(lhs: Self, rhs: Self) -> Self {
let modulus = Self::modulus();
let mut val = lhs.val() + rhs.val();
if val >= modulus {
val -= modulus;
}
Self::raw(val)
}
#[inline]
fn sub_impl(lhs: Self, rhs: Self) -> Self {
let modulus = Self::modulus();
let mut val = lhs.val().wrapping_sub(rhs.val());
if val >= modulus {
val = val.wrapping_add(modulus)
}
Self::raw(val)
}
fn mul_impl(lhs: Self, rhs: Self) -> Self;
#[inline]
fn div_impl(lhs: Self, rhs: Self) -> Self {
Self::mul_impl(lhs, rhs.inv())
}
}
impl<M: Modulus> InternalImplementations for StaticModInt<M> {
#[inline]
fn mul_impl(lhs: Self, rhs: Self) -> Self {
Self::raw((u64::from(lhs.val()) * u64::from(rhs.val()) % u64::from(M::VALUE)) as u32)
}
}
impl<I: Id> InternalImplementations for DynamicModInt<I> {
#[inline]
fn mul_impl(lhs: Self, rhs: Self) -> Self {
Self::raw(I::companion_barrett().mul(lhs.val, rhs.val))
}
}
macro_rules! impl_basic_traits {
() => {};
(impl <$generic_param:ident : $generic_param_bound:tt> _ for $self:ty; $($rest:tt)*) => {
impl <$generic_param: $generic_param_bound> Default for $self {
#[inline]
fn default() -> Self {
Self::default_impl()
}
}
impl <$generic_param: $generic_param_bound> FromStr for $self {
type Err = Infallible;
#[inline]
fn from_str(s: &str) -> Result<Self, Infallible> {
Self::from_str_impl(s)
}
}
impl<$generic_param: $generic_param_bound, V: RemEuclidU32> From<V> for $self {
#[inline]
fn from(from: V) -> Self {
Self::new(from)
}
}
#[allow(clippy::derive_hash_xor_eq)]
impl<$generic_param: $generic_param_bound> Hash for $self {
#[inline]
fn hash<H: Hasher>(&self, state: &mut H) {
Self::hash_impl(self, state)
}
}
impl<$generic_param: $generic_param_bound> fmt::Display for $self {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
Self::display_impl(self, f)
}
}
impl<$generic_param: $generic_param_bound> fmt::Debug for $self {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
Self::debug_impl(self, f)
}
}
impl<$generic_param: $generic_param_bound> Neg for $self {
type Output = $self;
#[inline]
fn neg(self) -> $self {
Self::neg_impl(self)
}
}
impl<$generic_param: $generic_param_bound> Neg for &'_ $self {
type Output = $self;
#[inline]
fn neg(self) -> $self {
<$self>::neg_impl(*self)
}
}
impl_basic_traits!($($rest)*);
};
}
impl_basic_traits! {
impl <M: Modulus> _ for StaticModInt<M> ;
impl <I: Id > _ for DynamicModInt<I>;
}
macro_rules! impl_bin_ops {
() => {};
(for<$($generic_param:ident : $generic_param_bound:tt),*> <$lhs_ty:ty> ~ <$rhs_ty:ty> -> $output:ty { { $lhs_body:expr } ~ { $rhs_body:expr } } $($rest:tt)*) => {
impl <$($generic_param: $generic_param_bound),*> Add<$rhs_ty> for $lhs_ty {
type Output = $output;
#[inline]
fn add(self, rhs: $rhs_ty) -> $output {
<$output>::add_impl(apply($lhs_body, self), apply($rhs_body, rhs))
}
}
impl <$($generic_param: $generic_param_bound),*> Sub<$rhs_ty> for $lhs_ty {
type Output = $output;
#[inline]
fn sub(self, rhs: $rhs_ty) -> $output {
<$output>::sub_impl(apply($lhs_body, self), apply($rhs_body, rhs))
}
}
impl <$($generic_param: $generic_param_bound),*> Mul<$rhs_ty> for $lhs_ty {
type Output = $output;
#[inline]
fn mul(self, rhs: $rhs_ty) -> $output {
<$output>::mul_impl(apply($lhs_body, self), apply($rhs_body, rhs))
}
}
impl <$($generic_param: $generic_param_bound),*> Div<$rhs_ty> for $lhs_ty {
type Output = $output;
#[inline]
fn div(self, rhs: $rhs_ty) -> $output {
<$output>::div_impl(apply($lhs_body, self), apply($rhs_body, rhs))
}
}
impl_bin_ops!($($rest)*);
};
}
macro_rules! impl_assign_ops {
() => {};
(for<$($generic_param:ident : $generic_param_bound:tt),*> <$lhs_ty:ty> ~= <$rhs_ty:ty> { _ ~= { $rhs_body:expr } } $($rest:tt)*) => {
impl <$($generic_param: $generic_param_bound),*> AddAssign<$rhs_ty> for $lhs_ty {
#[inline]
fn add_assign(&mut self, rhs: $rhs_ty) {
*self = *self + apply($rhs_body, rhs);
}
}
impl <$($generic_param: $generic_param_bound),*> SubAssign<$rhs_ty> for $lhs_ty {
#[inline]
fn sub_assign(&mut self, rhs: $rhs_ty) {
*self = *self - apply($rhs_body, rhs);
}
}
impl <$($generic_param: $generic_param_bound),*> MulAssign<$rhs_ty> for $lhs_ty {
#[inline]
fn mul_assign(&mut self, rhs: $rhs_ty) {
*self = *self * apply($rhs_body, rhs);
}
}
impl <$($generic_param: $generic_param_bound),*> DivAssign<$rhs_ty> for $lhs_ty {
#[inline]
fn div_assign(&mut self, rhs: $rhs_ty) {
*self = *self / apply($rhs_body, rhs);
}
}
impl_assign_ops!($($rest)*);
};
}
#[inline]
fn apply<F: FnOnce(X) -> O, X, O>(f: F, x: X) -> O {
f(x)
}
impl_bin_ops! {
for<M: Modulus> <StaticModInt<M> > ~ <StaticModInt<M> > -> StaticModInt<M> { { |x| x } ~ { |x| x } }
for<M: Modulus> <StaticModInt<M> > ~ <&'_ StaticModInt<M> > -> StaticModInt<M> { { |x| x } ~ { |&x| x } }
for<M: Modulus> <&'_ StaticModInt<M> > ~ <StaticModInt<M> > -> StaticModInt<M> { { |&x| x } ~ { |x| x } }
for<M: Modulus> <&'_ StaticModInt<M> > ~ <&'_ StaticModInt<M> > -> StaticModInt<M> { { |&x| x } ~ { |&x| x } }
for<I: Id > <DynamicModInt<I> > ~ <DynamicModInt<I> > -> DynamicModInt<I> { { |x| x } ~ { |x| x } }
for<I: Id > <DynamicModInt<I> > ~ <&'_ DynamicModInt<I>> -> DynamicModInt<I> { { |x| x } ~ { |&x| x } }
for<I: Id > <&'_ DynamicModInt<I>> ~ <DynamicModInt<I> > -> DynamicModInt<I> { { |&x| x } ~ { |x| x } }
for<I: Id > <&'_ DynamicModInt<I>> ~ <&'_ DynamicModInt<I>> -> DynamicModInt<I> { { |&x| x } ~ { |&x| x } }
for<M: Modulus, T: RemEuclidU32> <StaticModInt<M> > ~ <T> -> StaticModInt<M> { { |x| x } ~ { StaticModInt::<M>::new } }
for<I: Id , T: RemEuclidU32> <DynamicModInt<I> > ~ <T> -> DynamicModInt<I> { { |x| x } ~ { DynamicModInt::<I>::new } }
}
impl_assign_ops! {
for<M: Modulus> <StaticModInt<M> > ~= <StaticModInt<M> > { _ ~= { |x| x } }
for<M: Modulus> <StaticModInt<M> > ~= <&'_ StaticModInt<M> > { _ ~= { |&x| x } }
for<I: Id > <DynamicModInt<I>> ~= <DynamicModInt<I> > { _ ~= { |x| x } }
for<I: Id > <DynamicModInt<I>> ~= <&'_ DynamicModInt<I>> { _ ~= { |&x| x } }
for<M: Modulus, T: RemEuclidU32> <StaticModInt<M> > ~= <T> { _ ~= { StaticModInt::<M>::new } }
for<I: Id, T: RemEuclidU32> <DynamicModInt<I>> ~= <T> { _ ~= { DynamicModInt::<I>::new } }
}
macro_rules! impl_folding {
() => {};
(impl<$generic_param:ident : $generic_param_bound:tt> $trait:ident<_> for $self:ty { fn $method:ident(_) -> _ { _($unit:expr, $op:expr) } } $($rest:tt)*) => {
impl<$generic_param: $generic_param_bound> $trait<Self> for $self {
#[inline]
fn $method<S>(iter: S) -> Self
where
S: Iterator<Item = Self>,
{
iter.fold($unit, $op)
}
}
impl<'a, $generic_param: $generic_param_bound> $trait<&'a Self> for $self {
#[inline]
fn $method<S>(iter: S) -> Self
where
S: Iterator<Item = &'a Self>,
{
iter.fold($unit, $op)
}
}
impl_folding!($($rest)*);
};
}
impl_folding! {
impl<M: Modulus> Sum<_> for StaticModInt<M> { fn sum(_) -> _ { _(Self::raw(0), Add::add) } }
impl<M: Modulus> Product<_> for StaticModInt<M> { fn product(_) -> _ { _(Self::raw(1), Mul::mul) } }
impl<I: Id > Sum<_> for DynamicModInt<I> { fn sum(_) -> _ { _(Self::raw(0), Add::add) } }
impl<I: Id > Product<_> for DynamicModInt<I> { fn product(_) -> _ { _(Self::raw(1), Mul::mul) } }
}
#[cfg(test)]
mod tests {
use crate::modint::ModInt1000000007;
#[test]
fn static_modint_new() {
assert_eq!(0, ModInt1000000007::new(0u32).val);
assert_eq!(1, ModInt1000000007::new(1u32).val);
assert_eq!(1, ModInt1000000007::new(1_000_000_008u32).val);
assert_eq!(0, ModInt1000000007::new(0u64).val);
assert_eq!(1, ModInt1000000007::new(1u64).val);
assert_eq!(1, ModInt1000000007::new(1_000_000_008u64).val);
assert_eq!(0, ModInt1000000007::new(0usize).val);
assert_eq!(1, ModInt1000000007::new(1usize).val);
assert_eq!(1, ModInt1000000007::new(1_000_000_008usize).val);
assert_eq!(0, ModInt1000000007::new(0i64).val);
assert_eq!(1, ModInt1000000007::new(1i64).val);
assert_eq!(1, ModInt1000000007::new(1_000_000_008i64).val);
assert_eq!(1_000_000_006, ModInt1000000007::new(-1i64).val);
}
#[test]
fn static_modint_add() {
fn add(lhs: u32, rhs: u32) -> u32 {
(ModInt1000000007::new(lhs) + ModInt1000000007::new(rhs)).val
}
assert_eq!(2, add(1, 1));
assert_eq!(1, add(1_000_000_006, 2));
}
#[test]
fn static_modint_sub() {
fn sub(lhs: u32, rhs: u32) -> u32 {
(ModInt1000000007::new(lhs) - ModInt1000000007::new(rhs)).val
}
assert_eq!(1, sub(2, 1));
assert_eq!(1_000_000_006, sub(0, 1));
}
#[test]
fn static_modint_mul() {
fn mul(lhs: u32, rhs: u32) -> u32 {
(ModInt1000000007::new(lhs) * ModInt1000000007::new(rhs)).val
}
assert_eq!(1, mul(1, 1));
assert_eq!(4, mul(2, 2));
assert_eq!(999_999_937, mul(100_000, 100_000));
}
#[test]
fn static_modint_prime_div() {
fn div(lhs: u32, rhs: u32) -> u32 {
(ModInt1000000007::new(lhs) / ModInt1000000007::new(rhs)).val
}
assert_eq!(0, div(0, 1));
assert_eq!(1, div(1, 1));
assert_eq!(1, div(2, 2));
assert_eq!(23_809_524, div(1, 42));
}
#[test]
fn static_modint_sum() {
fn sum(values: &[i64]) -> ModInt1000000007 {
values.iter().copied().map(ModInt1000000007::new).sum()
}
assert_eq!(ModInt1000000007::new(-3), sum(&[-1, 2, -3, 4, -5]));
}
#[test]
fn static_modint_product() {
fn product(values: &[i64]) -> ModInt1000000007 {
values.iter().copied().map(ModInt1000000007::new).product()
}
assert_eq!(ModInt1000000007::new(-120), product(&[-1, 2, -3, 4, -5]));
}
#[test]
fn static_modint_binop_coercion() {
let f = ModInt1000000007::new;
let a = 10_293_812_usize;
let b = 9_083_240_982_usize;
assert_eq!(f(a) + f(b), f(a) + b);
assert_eq!(f(a) - f(b), f(a) - b);
assert_eq!(f(a) * f(b), f(a) * b);
assert_eq!(f(a) / f(b), f(a) / b);
}
#[test]
fn static_modint_assign_coercion() {
let f = ModInt1000000007::new;
let a = f(10_293_812_usize);
let b = 9_083_240_982_usize;
let expected = (((a + b) * b) - b) / b;
let mut c = a;
c += b;
c *= b;
c -= b;
c /= b;
assert_eq!(expected, c);
}
}
}
Submission Info
Submission Time
2023-05-17 21:56:30+0900
Task
C - Typical Stairs
User
bouzuya
Language
Rust (1.42.0)
Score
300
Code Size
51124 Byte
Status
AC
Exec Time
11 ms
Memory
3492 KiB
Compile Error
warning: field is never read: `sum_e`
--> src/main.rs:778:9
|
778 | pub(crate) sum_e: Vec<StaticModInt<M>>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: field is never read: `sum_ie`
--> src/main.rs:779:9
|
779 | pub(crate) sum_ie: Vec<StaticModInt<M>>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Judge Result
Set Name
Sample
All
Score / Max Score
0 / 0
300 / 300
Status
Set Name
Test Cases
Sample
s1.txt, s2.txt, s3.txt
All
01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, 25.txt, 26.txt, 27.txt, 28.txt, 29.txt, 30.txt, 31.txt, 32.txt, 33.txt, s1.txt, s2.txt, s3.txt
Case Name
Status
Exec Time
Memory
01.txt
AC 6 ms
2084 KiB
02.txt
AC 1 ms
2040 KiB
03.txt
AC 2 ms
2040 KiB
04.txt
AC 1 ms
2056 KiB
05.txt
AC 1 ms
2056 KiB
06.txt
AC 3 ms
2092 KiB
07.txt
AC 1 ms
2012 KiB
08.txt
AC 2 ms
2104 KiB
09.txt
AC 2 ms
2032 KiB
10.txt
AC 1 ms
2040 KiB
11.txt
AC 1 ms
2012 KiB
12.txt
AC 1 ms
2016 KiB
13.txt
AC 1 ms
1956 KiB
14.txt
AC 1 ms
2068 KiB
15.txt
AC 2 ms
2000 KiB
16.txt
AC 8 ms
3068 KiB
17.txt
AC 2 ms
2112 KiB
18.txt
AC 3 ms
2296 KiB
19.txt
AC 4 ms
2500 KiB
20.txt
AC 3 ms
2112 KiB
21.txt
AC 5 ms
2244 KiB
22.txt
AC 1 ms
2116 KiB
23.txt
AC 3 ms
2548 KiB
24.txt
AC 2 ms
2288 KiB
25.txt
AC 2 ms
2184 KiB
26.txt
AC 2 ms
2436 KiB
27.txt
AC 3 ms
2472 KiB
28.txt
AC 11 ms
3492 KiB
29.txt
AC 10 ms
2876 KiB
30.txt
AC 3 ms
2480 KiB
31.txt
AC 5 ms
2564 KiB
32.txt
AC 7 ms
2652 KiB
33.txt
AC 9 ms
2664 KiB
s1.txt
AC 1 ms
2036 KiB
s2.txt
AC 1 ms
2088 KiB
s3.txt
AC 1 ms
2064 KiB