結果
| 問題 | No.1507 Road Blocked |
| ユーザー |
 Moss_Local
|
| 提出日時 | 2021-05-14 22:45:42 |
| 言語 | Rust (1.77.0) |
| 結果 |
AC
|
| 実行時間 | 78 ms / 2,000 ms |
| コード長 | 16,086 bytes |
| コンパイル時間 | 3,633 ms |
| コンパイル使用メモリ | 173,048 KB |
| 実行使用メモリ | 24,960 KB |
| 最終ジャッジ日時 | 2024-04-10 01:50:24 |
| 合計ジャッジ時間 | 4,580 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge5 |
（要ログイン）
テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 1 ms
6,816 KB |
| testcase_01 | AC | 1 ms
6,820 KB |
| testcase_02 | AC | 1 ms
6,812 KB |
| testcase_03 | AC | 39 ms
24,960 KB |
| testcase_04 | AC | 71 ms
14,208 KB |
| testcase_05 | AC | 71 ms
14,208 KB |
| testcase_06 | AC | 76 ms
14,208 KB |
| testcase_07 | AC | 73 ms
14,080 KB |
| testcase_08 | AC | 74 ms
14,052 KB |
| testcase_09 | AC | 76 ms
14,208 KB |
| testcase_10 | AC | 75 ms
14,208 KB |
| testcase_11 | AC | 70 ms
14,208 KB |
| testcase_12 | AC | 72 ms
14,208 KB |
| testcase_13 | AC | 75 ms
14,208 KB |
| testcase_14 | AC | 69 ms
14,208 KB |
| testcase_15 | AC | 73 ms
14,176 KB |
| testcase_16 | AC | 72 ms
14,208 KB |
| testcase_17 | AC | 73 ms
14,080 KB |
| testcase_18 | AC | 75 ms
14,208 KB |
| testcase_19 | AC | 74 ms
14,208 KB |
| testcase_20 | AC | 75 ms
14,208 KB |
| testcase_21 | AC | 78 ms
14,208 KB |
| testcase_22 | AC | 74 ms
14,208 KB |
| testcase_23 | AC | 69 ms
14,208 KB |
| testcase_24 | AC | 74 ms
14,208 KB |
| testcase_25 | AC | 72 ms
14,116 KB |
| testcase_26 | AC | 74 ms
14,208 KB |
| testcase_27 | AC | 74 ms
14,080 KB |
| testcase_28 | AC | 71 ms
14,208 KB |
| testcase_29 | AC | 72 ms
14,208 KB |
| testcase_30 | AC | 72 ms
14,208 KB |
| testcase_31 | AC | 74 ms
14,192 KB |
| testcase_32 | AC | 75 ms
14,208 KB |
コンパイルメッセージ
warning: unnecessary parentheses around type
--> main.rs:70:15
|
70 | fn readi() -> (i64) {
| ^ ^
|
= note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
|
70 - fn readi() -> (i64) {
70 + fn readi() -> i64 {
|
warning: unused variable: `a2`
--> main.rs:454:14
|
454 | let (a2, e2) = mod_fact(k, p, fact);
| ^^ help: if this is intentional, prefix it with an underscore: `_a2`
|
= note: `#[warn(unused_variables)]` on by default
warning: unused variable: `a2`
--> main.rs:502:18
|
502 | let (a2, e2) = mod_fact(k, p, &self.f_table);
| ^^ help: if this is intentional, prefix it with an underscore: `_a2`
warning: unused variable: `i`
--> main.rs:614:9
|
614 | for i in 0..n - 1 {
| ^ help: if this is intentional, prefix it with an underscore: `_i`
warning: variable `root` is assigned to, but never used
--> main.rs:623:13
|
623 | let mut root = 0 as usize;
| ^^^^
|
= note: consider using `_root` instead
warning: value assigned to `root` is never read
--> main.rs:626:13
|
626 | root = i;
| ^^^^
|
= help: maybe it is overwritten before being read?
= note: `#[warn(unused_assignments)]` on by default
warning: variable does not need to be mutable
--> main.rs:641:13
|
641 | let mut x = data[i] as i64;
| ----^
| |
| help: remove this `mut`
|
= note: `#[warn(unused_mut)]` on by default
warning: 7 warnings emitted
ソースコード
// -*- coding:utf-8-unix -*-
// #![feature(map_first_last)]
#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_macros)]
use std::collections::*;
use std::convert::*;
use std::convert::{From, Into};
use std::fmt::Debug;
use std::fs::File;
use std::io::prelude::*;
use std::io::*;
use std::marker::Copy;
use std::mem::*;
use std::ops::Bound::*;
use std::ops::{Add, Mul, Neg, Sub};
use std::str;
use std::vec;
use std::{cmp, process::Output};
use std::{cmp::Ordering, env::consts::DLL_PREFIX};
use std::{cmp::Ordering::*, f32::consts::PI};
const INF: i64 = 1223372036854775807;
const UINF: usize = INF as usize;
const FINF: f64 = 122337203685.0;
const INF128: i128 = 1223372036854775807000000000000;
const LINF: i64 = 2147483647;
// const MOD: i64 = 1000000007;
const MOD: i64 = 998244353;
const UMOD: usize = MOD as usize;
use std::cmp::*;
use std::collections::*;
use std::io::stdin;
use std::io::stdout;
use std::io::Write;
macro_rules! p {
($x:expr) => {
println!("{}", $x);
};
}
macro_rules! d {
($x:expr) => {
dbg!($x);
};
}
macro_rules! v {
($x:expr) => {
if $x == 0 {
vec![];
} else if $x == 1 {
BTreeSet::new();
} else if $x == 2 {
BTreeMap::new();
}
};
}
// use str::Chars;
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
let mut s = String::new();
std::io::stdin().read_line(&mut s).ok();
s.trim().parse().ok().unwrap()
}
#[allow(dead_code)]
fn readi() -> (i64) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
iter.next().unwrap().parse::<i64>().unwrap()
}
#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
read::<String>()
.split_whitespace()
.map(|e| e.parse().ok().unwrap())
.collect()
}
#[allow(dead_code)]
fn read_vec2<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
(0..n).map(|_| read_vec()).collect()
}
#[allow(dead_code)]
fn readii() -> (i64, i64) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
)
}
fn readff() -> (f64, f64) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<f64>().unwrap(),
iter.next().unwrap().parse::<f64>().unwrap(),
)
}
#[allow(dead_code)]
fn readiii() -> (i64, i64, i64) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
)
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
)
}
fn readcc() -> (char, char) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<char>().unwrap(),
iter.next().unwrap().parse::<char>().unwrap(),
)
}
#[allow(dead_code)]
fn readuuu() -> (usize, usize, usize) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
)
}
#[allow(dead_code)]
fn readuuuu() -> (usize, usize, usize, usize) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
iter.next().unwrap().parse::<usize>().unwrap(),
)
}
fn readiiii() -> (i64, i64, i64, i64) {
let mut str = String::new();
let _ = stdin().read_line(&mut str).unwrap();
let mut iter = str.split_whitespace();
(
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
iter.next().unwrap().parse::<i64>().unwrap(),
)
}
macro_rules! M {
(a :expr ) => {
M::new({ a })
};
}
#[derive(Copy, Clone)]
pub struct M(i64);
impl M {
fn new(x: i64) -> Self {
M(x.rem_euclid(MOD))
}
fn pow(self, n: usize) -> Self {
match n {
0 => M::new(1),
_ => {
let mut a = self.pow(n >> 1);
a *= a;
if n & 1 == 1 {
a *= self;
}
a
}
}
}
fn inv(self) -> Self {
self.pow((MOD - 2) as usize)
}
}
impl std::ops::Neg for M {
type Output = M;
fn neg(self) -> Self::Output {
Self::new(-self.0)
}
}
impl std::ops::AddAssign<M> for M {
fn add_assign(&mut self, rhs: Self) {
self.0 += rhs.0;
self.0 %= MOD;
}
}
impl std::ops::AddAssign<i64> for M {
fn add_assign(&mut self, rhs: i64) {
*self += M::new(rhs);
}
}
impl std::ops::AddAssign<usize> for M {
fn add_assign(&mut self, rhs: usize) {
*self += M::new(rhs as i64);
}
}
impl<T> std::ops::Add<T> for M
where
M: std::ops::AddAssign<T>,
{
type Output = Self;
fn add(self, other: T) -> Self {
let mut res = self;
res += other;
res
}
}
impl std::ops::SubAssign<M> for M {
fn sub_assign(&mut self, rhs: Self) {
self.0 -= rhs.0;
if self.0 < 0 {
self.0 += MOD;
}
}
}
impl std::ops::SubAssign<i64> for M {
fn sub_assign(&mut self, rhs: i64) {
*self -= M::new(rhs);
if (*self).0 < 0 {
self.0 += MOD;
}
}
}
impl std::ops::SubAssign<usize> for M {
fn sub_assign(&mut self, rhs: usize) {
*self -= M::new(rhs as i64);
if (*self).0 < 0 {
self.0 += MOD;
}
}
}
impl<T> std::ops::Sub<T> for M
where
M: std::ops::SubAssign<T>,
{
type Output = Self;
fn sub(self, other: T) -> Self {
let mut res = self;
res -= other;
res
}
}
impl std::ops::MulAssign<M> for M {
fn mul_assign(&mut self, rhs: Self) {
self.0 *= rhs.0;
self.0 %= MOD;
}
}
impl std::ops::MulAssign<i64> for M {
fn mul_assign(&mut self, rhs: i64) {
*self *= M::new(rhs);
}
}
impl std::ops::MulAssign<usize> for M {
fn mul_assign(&mut self, rhs: usize) {
*self *= M::new(rhs as i64);
}
}
impl<T> std::ops::Mul<T> for M
where
M: std::ops::MulAssign<T>,
{
type Output = Self;
fn mul(self, other: T) -> Self {
let mut res = self;
res *= other;
res
}
}
impl std::ops::DivAssign<M> for M {
fn div_assign(&mut self, rhs: Self) {
*self *= rhs.inv();
}
}
impl std::ops::DivAssign<i64> for M {
fn div_assign(&mut self, rhs: i64) {
*self /= M::new(rhs);
}
}
impl std::ops::DivAssign<usize> for M {
fn div_assign(&mut self, rhs: usize) {
*self /= M::new(rhs as i64);
}
}
impl<T> std::ops::Div<T> for M
where
M: std::ops::DivAssign<T>,
{
type Output = Self;
fn div(self, other: T) -> Self {
let mut res = self;
res /= other;
res
}
}
impl std::fmt::Display for M {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.0)
}
}
impl std::ops::Deref for M {
type Target = i64;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl std::ops::DerefMut for M {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
#[allow(dead_code)]
pub fn gcd(a: usize, b: usize) -> usize {
if b == 0 {
a
} else {
gcd(b, a % b)
}
}
#[allow(dead_code)]
pub fn lcm(a: usize, b: usize) -> usize {
a / gcd(a, b) * b
}
#[allow(dead_code)]
/// (gcd, x, y)
pub fn extgcd(a: i64, b: i64) -> (i64, i64, i64) {
if b == 0 {
(a, 1, 0)
} else {
let (gcd, x, y) = extgcd(b, a % b);
(gcd, y, x - (a / b) * y)
}
}
#[allow(dead_code)]
/// x ^ n % m
pub fn mod_pow(x: usize, n: usize, m: usize) -> usize {
let mut res = 1;
let mut x = x % m;
let mut n = n;
while n > 0 {
if n & 1 == 1 {
res = (res * x) % m;
}
x = (x * x) % m;
n >>= 1;
}
res
}
#[allow(dead_code)]
pub fn mod_inverse(a: usize, m: usize) -> usize {
let (_, x, _) = extgcd(a as i64, m as i64);
((m as i64 + x) as usize % m) % m
}
#[allow(dead_code)]
pub fn fact_table(len: usize, m: usize) -> Vec<usize> {
let mut res = vec![1; len + 1];
for i in 1..len + 1 {
res[i] = (i as usize * res[i - 1]) % m;
}
res
}
#[allow(dead_code)]
/// Factorial and Inverse factorial table
pub fn fact_inv_table(size: usize, m: usize) -> (Vec<usize>, Vec<usize>) {
let mut fact = vec![1; size];
let mut fact_inv = vec![1; size];
for i in 2..size {
fact[i] = fact[i - 1] * i as usize % m;
fact_inv[i] = m - ((m / i as usize) * fact_inv[(m % i as usize) as usize] % m);
}
for i in 1..size {
fact_inv[i] = fact_inv[i - 1] * fact_inv[i] % m;
}
(fact, fact_inv)
}
#[allow(dead_code)]
/// (a mod p, e when n! = a p\^e)
pub fn mod_fact(n: usize, p: usize, fact: &[usize]) -> (usize, usize) {
if n == 0 {
(1, 0)
} else {
let (a, b) = mod_fact(n / p, p, fact);
let pow = b + n / p;
if n / p % 2 != 0 {
(a * (p - fact[(n % p) as usize]) % p, pow)
} else {
(a * fact[(n % p) as usize] % p, pow)
}
}
}
#[allow(dead_code)]
/// C(n, k) % p
pub fn mcom(n: usize, k: usize, fact: &[usize]) -> usize {
let p = MOD as usize;
if k == 0 {
return 1;
}
if n < k {
0
} else {
let (a1, e1) = mod_fact(n, p, fact);
let (a2, e2) = mod_fact(k, p, fact);
let (a3, e3) = mod_fact(n - k, p, fact);
if e1 > e2 + e3 {
0
} else {
a1 * mod_inverse(a2 * a3 % p, p) % p
}
}
}
pub fn mperm(n: usize, k: usize, fact: &[usize]) -> usize {
let p = MOD as usize;
if k == 0 {
return 1;
}
if n < k {
0
} else {
let (a1, e1) = mod_fact(n, p, fact);
let (a2, e2) = mod_fact(k, p, fact);
let (a3, e3) = mod_fact(n - k, p, fact);
if e1 > e2 + e3 {
0
} else {
a1 * mod_inverse(a3 % p, p) % p
}
}
}
pub fn hcom(n: usize, k: usize, fact: &[usize]) -> usize {
return mcom(n + k - 1, k, fact);
}
pub struct Combination {
m: usize,
f_table: Vec<usize>,
}
impl Combination {
// 0 <= size <= 10^8 is constrained.
pub fn new(mod_num: usize, table_size: usize) -> Self {
Self {
m: mod_num,
f_table: vec![0; table_size],
}
}
pub fn build(&mut self) {
let size = self.f_table.len();
self.f_table = fact_table(size, self.m);
}
fn fact_table(len: usize, m: usize) -> Vec<usize> {
let mut res = vec![1; len + 1];
for i in 1..len + 1 {
res[i] = (i as usize * res[i - 1]) % m;
}
res
}
pub fn p(&mut self, n: usize, k: usize) -> usize {
let p = MOD as usize;
if k == 0 {
return 1;
}
if n < k {
0
} else {
let (a1, e1) = mod_fact(n, p, &self.f_table);
let (a2, e2) = mod_fact(k, p, &self.f_table);
let (a3, e3) = mod_fact(n - k, p, &self.f_table);
if e1 > e2 + e3 {
0
} else {
a1 * mod_inverse(a3 % p, p) % p
}
}
}
pub fn c(&mut self, n: usize, k: usize) -> usize {
let p = MOD as usize;
if n == 0 {
return 0;
}
if k == 0 {
return 1;
}
if n < k {
0
} else {
let (a1, e1) = mod_fact(n, p, &self.f_table);
let (a2, e2) = mod_fact(k, p, &self.f_table);
let (a3, e3) = mod_fact(n - k, p, &self.f_table);
if e1 > e2 + e3 {
0
} else {
a1 * mod_inverse(a2 * a3 % p, p) % p
}
}
}
pub fn h(&mut self, n: usize, k: usize) -> usize {
return mcom(n + k - 1, k, &self.f_table);
}
pub fn factorial(&mut self, n: usize) -> usize {
return self.p(n, n);
}
fn extgcd(a: i64, b: i64) -> (i64, i64, i64) {
if b == 0 {
(a, 1, 0)
} else {
let (gcd, x, y) = extgcd(b, a % b);
(gcd, y, x - (a / b) * y)
}
}
pub fn mod_inverse(a: usize, m: usize) -> usize {
let (_, x, _) = extgcd(a as i64, m as i64);
((m as i64 + x) as usize % m) % m
}
fn mod_fact(&mut self, n: usize, p: usize, fact: &[usize]) -> (usize, usize) {
if n == 0 {
(1, 0)
} else {
let (a, b) = mod_fact(n / p, p, fact);
let pow = b + n / p;
if n / p % 2 != 0 {
(a * (p - fact[(n % p) as usize]) % p, pow)
} else {
(a * fact[(n % p) as usize] % p, pow)
}
}
}
}
fn djikstra(graph: &Vec<Vec<(usize, usize)>>, start: usize) -> Vec<usize> {
let mut dist = vec![INF as usize; graph.len()];
let mut heap = BinaryHeap::new();
heap.push(Reverse((0 as usize, start)));
dist[start] = 0;
while let Some(Reverse(x)) = heap.pop() {
let cost = x.0;
let v = x.1;
if cost > dist[v] {
continue;
}
for edge in &graph[v] {
let nc = cost + edge.1;
let nv = edge.0;
if nc < dist[nv] {
heap.push(Reverse((nc, nv)));
dist[nv] = nc;
}
}
}
return dist;
}
fn dfs(v: usize, graph: &Vec<Vec<(usize, usize)>>, used: &mut Vec<usize>, data: &mut Vec<usize>) {
used[v] = 1;
let mut res = 0 as usize;
for i in graph[v].iter() {
let nv = (*i).0;
if used[nv] == 1 {
continue;
}
dfs(nv, &graph, used, data);
res += data[nv];
}
res += 1;
data[v] = res;
return;
}
fn solve() {
let n: usize = read();
let mut graph = vec![vec![(0 as usize, 0 as usize); (0) as usize]; (n) as usize];
let mut data = vec![0; n];
if n == 2 {
println!("{:?}", 0);
return;
}
for i in 0..n - 1 {
let (mut a, mut b) = readuu();
a -= 1;
b -= 1;
graph[a].push((b, 1));
graph[b].push((a, 1));
data[a] += 1;
data[b] += 1;
}
let mut root = 0 as usize;
for i in 0..n {
if data[i] == 1 {
root = i;
}
}
// let mut d = djikstra(&graph, root);
// d!(d.clone());
let mut used = vec![0; n];
let mut data = vec![0; n];
dfs(0, &graph, &mut used, &mut data);
let mut res = M(1);
res *= M(((n as i64) * (n as i64 - 1) / 2) as i64);
res *= M(n as i64 - 1);
// println!("{:?}", data.clone());
// println!("{:?}", res.0);
for i in 1..n {
let mut x = data[i] as i64;
res -= M(n as i64 - x) * x;
}
// println!("{:?}", res.0);
res /= M(((n as i64) * (n as i64 - 1) / 2) as i64);
res /= M(n as i64 - 1);
println!("{:?}", res.0);
return;
}
fn main() {
solve();
}