結果
| 問題 | No.1081 和の和 |
| コンテスト | |
| ユーザー |
 elphe
|
| 提出日時 | 2026-06-14 15:32:04 |
| 言語 | Rust (1.94.0 + proconio + num + itertools) |
| 結果 |
AC
|
| 実行時間 | 1 ms / 2,000 ms |
| コード長 | 18,218 bytes |
| 記録 | |
| コンパイル時間 | 3,567 ms |
| コンパイル使用メモリ | 199,128 KB |
| 実行使用メモリ | 6,400 KB |
| 最終ジャッジ日時 | 2026-06-14 15:32:14 |
| 合計ジャッジ時間 | 6,254 ms |
|
ジャッジサーバーID （参考情報） |
judge1_1 / judge2_1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 8 |
ソースコード
fn main() {
let stdin = std::io::read_to_string(std::io::stdin().lock()).unwrap();
let mut stdin = stdin.split_ascii_whitespace();
unsafe {
read!(stdin -> (n: u8, a: Vec[u32; n]));
write!(output(solve(a)));
}
}
fn solve(a: Vec<u32>) -> u32 {
const MOD: u32 = 1_000_000_007;
let n = a.len();
let factorial_of = mylib::make_factorial_of::<MOD>(n - 1);
a.into_iter().enumerate().fold(0, |acc, (i, a)| {
(acc + (a as u64 * *factorial_of.last().unwrap() as u64 % MOD as u64
* mylib::pow_mod(
(factorial_of[i] as u64 * factorial_of[(n - 1) - i] as u64 % MOD as u64) as u32,
MOD - 2,
MOD,
) as u64
% MOD as u64) as u32)
% MOD
})
}
fn output(ans: u32) -> String {
format!("{}", ans)
}
mod mylib {
pub fn make_factorial_of<const MOD: u32>(max_idx: usize) -> Vec<u32> {
let mut prod = 1;
[1].into_iter()
.chain((1..=max_idx).map(|i| {
prod = (prod as u64 * i as u64 % MOD as u64) as u32;
prod
}))
.collect()
}
pub const fn pow_mod(a: u32, mut b: u32, r#mod: u32) -> u32 {
let mut ans: u32 = 1;
let mut mul: u32 = a;
while b > 0 {
if (b & 1) == 1 {
ans = (ans as u64 * mul as u64 % r#mod as u64) as u32;
}
mul = (mul as u64 * mul as u64 % r#mod as u64) as u32;
b /= 2;
}
ans
}
}
#[macro_export]
macro_rules! read {
($iter:ident -> ($v:ident : $t1:tt $([$($t2:tt)+] $({$($t3:tt)+})?)?)) => {
let $v = read_value!($iter -> $t1 $([$($t2)+] $({$($t3)+})? )?);
};
($iter:ident -> ($v:ident : $t1:tt $([$($t2:tt)+] $({$($t3:tt)+})?)? , $($r:tt)*)) => {
read!($iter -> ($v : $t1 $([$($t2)+] $({$($t3)+})?)?));
read!($iter -> ($($r)*));
};
}
#[macro_export]
macro_rules! read_value {
($source:ident -> ($($t1:tt $([$($t2:tt)+])?),+)) => {
( $(read_value!($source -> $t1 $([$($t2)+])?)),* )
};
($source:ident -> [ $t1:tt ; $len:expr ]) => {
{
let mut x: [::std::mem::MaybeUninit<$t1>; $len] = ::std::mem::MaybeUninit::uninit().assume_init();
for elem in x.iter_mut() {
elem.as_mut_ptr().write(read_value!($source -> $t1));
}
::std::mem::transmute::<[::std::mem::MaybeUninit<$t1>; $len], [$t1; $len]>(x)
}
};
($source:ident -> [ $c2:tt [ $t1:tt $(; $len2:expr)? ] ; $len1:expr ]) => {
{
let mut x: [::std::mem::MaybeUninit<$c2<$t1>>; $len1] = unsafe { ::std::mem::MaybeUninit::uninit().assume_init() };
for elem in x.iter_mut() {
elem.as_mut_ptr().write(read_value!($source -> $c2 [ $t1 $(; $len2)? ]));
}
::std::mem::transmute::<[::std::mem::MaybeUninit<$c2<$t1>>; $len1], [$c2<$t1>; $len1]>(x)
}
};
($source:ident -> $t1:tt[ $t2:tt $([$($t3:tt)+])? ; $len:expr ]) => {
(0..($len)).map(|_| read_value!($source -> $t2 $([$($t3)+])?)).collect::<$t1<_>>()
};
($source:ident -> $t1:tt[ $t2:tt $([$($t3:tt)+])? ]) => {
(0..(read_value!($source -> u32))).map(|_| read_value!($source -> $t2 $([$($t3)+])?)).collect::<$t1<_>>()
};
($source:ident -> $t1:tt[ ($($t2:tt),+) ; $len:expr ] { $($p1:pat => ($($pos:tt),*)),* }) => {
(0..($len)).map(|_| {
let mut v = ($($t2::default()),+);
v.0 = my_parser::parse_without_checking(($source).next().unwrap());
match v.0 {
$($p1 => {
$(v.$pos = my_parser::parse_without_checking(($source).next().unwrap()));*
}),*
_ => unreachable!(),
}
v
}).collect::<$t1<_>>()
};
($source:ident -> $t1:tt[ ($($t2:tt),+) ] { $($p1:pat => ($($pos:tt),*)),* }) => {
read_value!($source -> $t1[ ($($t2),+) ; read_value!($source -> u32) ] { $($p1 => ($($pos),*)),* })
};
($source:ident -> $t:ty) => {
my_parser::parse_without_checking::<$t>(($source).next().unwrap())
};
}
mod my_parser {
#[allow(unused)]
pub unsafe fn parse_without_checking<F: std::str::FromStr + Parsable>(target: &str) -> F {
unsafe { Parsable::from_str(target) }
}
pub trait Parsable {
unsafe fn from_str(s: &str) -> Self;
}
impl Parsable for String {
unsafe fn from_str(s: &str) -> Self {
Self::from(s)
}
}
impl Parsable for char {
unsafe fn from_str(s: &str) -> Self {
s.chars().next().unwrap()
}
}
macro_rules! parse_float {
($s:ident) => {{
let mut iter = $s.bytes().peekable();
let sign = match iter.peek().unwrap() {
b'-' => {
iter.next();
-1.0
}
b'+' => {
iter.next();
1.0
}
_ => 1.0,
};
let mut result = 0.0;
while let Some(cur) = iter.next()
&& cur != b'.'
{
result = result * 10.0 + (cur - b'0') as Self;
}
let mut digit = 1.0;
(result
+ iter
.map(|cur| {
digit *= 0.1;
digit * (cur - b'0') as Self
})
.sum::<Self>())
* sign
}};
}
impl Parsable for u8 {
unsafe fn from_str(s: &str) -> Self {
((((s.bytes().fold(0, |acc, x| (acc << 8) | (x as u32)) & 0x0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16) as Self
}
}
impl Parsable for u16 {
unsafe fn from_str(s: &str) -> Self {
((((((s.bytes().fold(0, |acc, x| (acc << 8) | (x as u64)) & 0x0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32) as Self
}
}
impl Parsable for u32 {
unsafe fn from_str(s: &str) -> Self {
((((((((s.bytes().fold(0, |acc, x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64) as Self
}
}
impl Parsable for u64 {
unsafe fn from_str(s: &str) -> Self {
const POW_10: [u64; 17] = [
1,
10,
100,
1_000,
10_000,
100_000,
1_000_000,
10_000_000,
100_000_000,
1_000_000_000,
10_000_000_000,
100_000_000_000,
1_000_000_000_000,
10_000_000_000_000,
100_000_000_000_000,
1_000_000_000_000_000,
10_000_000_000_000_000,
];
s.as_bytes().chunks(16).fold(0, |acc, x| {
acc * POW_10[x.len()]
+ ((((((((x.into_iter().fold(0, |acc, &x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64) as Self
})
}
}
impl Parsable for u128 {
unsafe fn from_str(s: &str) -> Self {
const POW_10: [u128; 17] = [
1,
10,
100,
1_000,
10_000,
100_000,
1_000_000,
10_000_000,
100_000_000,
1_000_000_000,
10_000_000_000,
100_000_000_000,
1_000_000_000_000,
10_000_000_000_000,
100_000_000_000_000,
1_000_000_000_000_000,
10_000_000_000_000_000,
];
s.as_bytes().chunks(16).fold(0, |acc, x| {
acc * POW_10[x.len()]
+ ((((((((x.into_iter().fold(0, |acc, &x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64) as Self
})
}
}
impl Parsable for i8 {
unsafe fn from_str(s: &str) -> Self {
((((((s
.bytes()
.skip(match s.as_bytes()[0].is_ascii_digit() {
true => 0,
false => 1,
})
.fold(0, |acc, x| (acc << 8) | (x as u32))
& 0x0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16) as i32)
* match s.as_bytes()[0] == b'-' {
true => -1,
false => 1,
}) as Self
}
}
impl Parsable for i16 {
unsafe fn from_str(s: &str) -> Self {
((((((((s
.bytes()
.skip(match s.as_bytes()[0].is_ascii_digit() {
true => 0,
false => 1,
})
.fold(0, |acc, x| (acc << 8) | (x as u64))
& 0x0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32) as i64)
* match s.as_bytes()[0] == b'-' {
true => -1,
false => 1,
}) as Self
}
}
impl Parsable for i32 {
unsafe fn from_str(s: &str) -> Self {
((((((((((s
.bytes()
.skip(match s.as_bytes()[0].is_ascii_digit() {
true => 0,
false => 1,
})
.fold(0, |acc, x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64) as i128)
* match s.as_bytes()[0] == b'-' {
true => -1,
false => 1,
}) as Self
}
}
impl Parsable for i64 {
unsafe fn from_str(s: &str) -> Self {
const POW_10: [u64; 17] = [
1,
10,
100,
1_000,
10_000,
100_000,
1_000_000,
10_000_000,
100_000_000,
1_000_000_000,
10_000_000_000,
100_000_000_000,
1_000_000_000_000,
10_000_000_000_000,
100_000_000_000_000,
1_000_000_000_000_000,
10_000_000_000_000_000,
];
let skip = match s.as_bytes()[0].is_ascii_digit() {
true => 0,
false => 1,
};
((s.as_bytes()[skip..].chunks(16).fold(0, |acc, x| {
acc * POW_10[x.len()]
+ ((((((((x.into_iter().fold(0, |acc, &x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64) as u64
}) as i64)
* match s.as_bytes()[0] == b'-' {
true => -1,
false => 1,
}) as Self
}
}
impl Parsable for i128 {
unsafe fn from_str(s: &str) -> Self {
const POW_10: [u128; 17] = [
1,
10,
100,
1_000,
10_000,
100_000,
1_000_000,
10_000_000,
100_000_000,
1_000_000_000,
10_000_000_000,
100_000_000_000,
1_000_000_000_000,
10_000_000_000_000,
100_000_000_000_000,
1_000_000_000_000_000,
10_000_000_000_000_000,
];
let skip = match s.as_bytes()[0].is_ascii_digit() {
true => 0,
false => 1,
};
((s.as_bytes()[skip..].chunks(16).fold(0, |acc, x| {
acc * POW_10[x.len()]
+ ((((((((x.into_iter().fold(0, |acc, &x| (acc << 8) | (x as u128))
& 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)
.wrapping_mul((1 << 8) + 10)
>> 8)
& 0x00ff00ff00ff00ff00ff00ff00ff00ff)
.wrapping_mul((1 << 16) + 100)
>> 16)
& 0x0000ffff0000ffff0000ffff0000ffff)
.wrapping_mul((1 << 32) + 10000)
>> 32)
& 0x00000000ffffffff00000000ffffffff)
.wrapping_mul((1 << 64) + 100000000)
>> 64)
}) as i128)
* match s.as_bytes()[0] == b'-' {
true => -1,
false => 1,
}) as Self
}
}
impl Parsable for f32 {
unsafe fn from_str(s: &str) -> Self {
parse_float!(s)
}
}
impl Parsable for f64 {
unsafe fn from_str(s: &str) -> Self {
parse_float!(s)
}
}
}
#[macro_export]
macro_rules! write {
($out:expr) => {{
use std::io::Write;
std::io::stdout()
.lock()
.write_all(($out).as_bytes())
.unwrap();
}};
}
#[macro_export]
macro_rules! format_iter {
($i:expr, $sep:expr, ($($elem:ident),+) -> ($form:expr $(, $ex:expr)*)) => {{
#[allow(unused_parens)]
let ($($elem),+) = i.next().unwrap();
#[allow(unused_parens)]
$i.fold(std::format!($form $(, $ex)*), |mut acc, ($($elem),+)| {
use std::fmt::Write;
acc.push_str($sep);
std::write!(&mut acc, $form $(, $ex)*).unwrap();
acc
})
}}
}
#[macro_export]
macro_rules! format_vec {
($v:expr, $sep:expr, ($($elem:ident),+) -> ($form:expr $(, $ex:expr)*)) => {{
if $v.is_empty() {
String::new()
} else {
#[allow(unused_parens)]
let ($($elem),+) = $v[0].clone();
#[allow(unused_parens)]
$v.into_iter().skip(1).fold(std::format!($form $(, $ex)*), |mut acc, ($($elem),+)| {
use std::fmt::Write;
acc.push_str($sep);
std::write!(&mut acc, $form $(, $ex)*).unwrap();
acc
})}
}}
}
#[macro_export]
macro_rules! format_vec_vec {
($v:expr, $sep1:expr, $sep2:expr, ($($elem:ident),+) -> ($form:expr $(, $ex:expr)*)) => {{
let mut v = $v;
let v_first = v.drain(..1).next().unwrap();
#[allow(unused_parens)]
v.into_iter().fold(format_vec!(v_first, $sep2, ($($elem),+) -> ($form $(, $ex)*)), |mut acc, mut v| {
use std::fmt::Write;
acc.push_str($sep1);
let ($($elem),+) = v.drain(..1).next().unwrap();
std::write!(&mut acc, $form $(, $ex)*).unwrap();
v.into_iter().skip(1).fold(acc, |mut acc, ($($elem),+)| {
acc.push_str($sep2);
std::write!(&mut acc, $form $(, $ex)*).unwrap();
acc
})
})
}}
}