結果
問題 | No.778 クリスマスツリー |
ユーザー |
|
提出日時 | 2021-04-01 19:50:59 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 126 ms / 2,000 ms |
コード長 | 14,963 bytes |
コンパイル時間 | 13,793 ms |
コンパイル使用メモリ | 397,544 KB |
実行使用メモリ | 36,676 KB |
最終ジャッジ日時 | 2024-12-18 00:53:22 |
合計ジャッジ時間 | 16,179 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 12 |
ソースコード
fn main() {let mut io = IO::new();input!{ from io,n: usize,p: [usize; n-1]}let mut g = UndirectedGraph::new(n);for i in 0..n-1 {g.add_edge(p[i], i+1, Void());}let euler = tree_dfs(&g, 0).3;let mut bit = FenwickTree::<i64>::new(n);let mut ans = 0;for &v in &euler {if v < n {ans += bit.sum(..v);bit.add(v, 1);} else {bit.add(!v, -1);}}io.println(ans);}pub fn tree_dfs<C: Cost, G: Graph<C>>(g: &G, root: usize)-> (Vec<C>, Vec<Option<usize>>, Vec<usize>, Vec<usize>){let n = g.size();let mut euler = Vec::with_capacity(n);let mut dist = vec![C::MAX; n];dist[root] = C::zero();let mut par = vec![None; n];let mut size = vec![1; n];let mut q = vec![root];while let Some(v) = q.pop() {euler.push(v);if v < n {q.push(!v);for e in g.edges_from(v) {if par[v] == Some(e.to) { continue; }par[e.to] = Some(v);dist[e.to] = dist[v] + e.cost;q.push(e.to);}}}for &v in euler.iter().skip(1).filter(|&&v| v < n).rev() {size[par[v].unwrap()] += size[v];}(dist, par, size, euler)}// ------------ Graph impl start ------------pub trait Cost:Element+ Clone + Copy + std::fmt::Display+ Eq + Ord+ Zero + One+ Add<Output = Self> + AddAssign+ Sub<Output = Self>+ Neg<Output = Self>{const MAX: Self;}#[derive(Copy, Clone)]pub struct Edge<C = Void> {// pub from: usize,pub to: usize,pub cost: C,pub id: usize}pub struct UndirectedGraph<C>(pub Vec<Vec<Edge<C>>>, pub usize);pub struct DirectedGraph<C>{pub forward: Vec<Vec<Edge<C>>>,pub backward: Vec<Vec<Edge<C>>>,pub count: usize,}pub trait Graph<C: Element> {fn new(size: usize) -> Self;fn size(&self) -> usize;fn add_edge(&mut self, u: usize, v: usize, cost: C);fn edges_from(&self, v: usize) -> std::slice::Iter<Edge<C>>;}impl<C: Element> Graph<C> for UndirectedGraph<C> {fn new(size: usize) -> Self {Self(vec![Vec::<Edge<C>>::new(); size], 0)}fn size(&self) -> usize {self.0.len()}fn add_edge(&mut self, u: usize, v: usize, cost: C) {self.0[u].push(Edge{ to: v, cost: cost.clone(), id: self.1 });self.0[v].push(Edge{ to: u, cost: cost.clone(), id: self.1 });self.1 += 1;}fn edges_from(&self, v: usize) -> std::slice::Iter<Edge<C>> {self.0[v].iter()}}impl<C: Element> Graph<C> for DirectedGraph<C> {fn new(size: usize) -> Self {Self {forward: vec![Vec::<Edge<C>>::new(); size],backward: vec![Vec::<Edge<C>>::new(); size],count: 0}}fn size(&self) -> usize {self.forward.len()}fn add_edge(&mut self, u: usize, v: usize, cost: C) {self.forward[u].push(Edge{ to: v, cost: cost.clone(), id: self.count });self.backward[v].push(Edge{ to: u, cost: cost.clone(), id: self.count });self.count += 1;}fn edges_from(&self, v: usize) -> std::slice::Iter<Edge<C>> {self.forward[v].iter()}}impl<C: Element> DirectedGraph<C> {pub fn edges_to(&self, u: usize) -> std::slice::Iter<Edge<C>> {self.backward[u].iter()}pub fn reverse(&self) -> Self {Self {forward: self.backward.clone(),backward: self.forward.clone(),count: self.count,}}}macro_rules! impl_cost {($($T:ident,)*) => {$(impl Cost for $T { const MAX: Self = std::$T::MAX; })*};}impl_cost! {i8, i16, i32, i64, i128, isize,}#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]pub struct Void();impl std::fmt::Display for Void {fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {write!(f, "")}}impl Zero for Void {fn zero() -> Self { Void() }fn is_zero(&self) -> bool { true }}impl One for Void {fn one() -> Self { Void() }fn is_one(&self) -> bool { true }}impl Add for Void {type Output = Self;fn add(self, _: Self) -> Self { Void() }}impl AddAssign for Void {fn add_assign(&mut self, _: Self) {}}impl Sub for Void {type Output = Self;fn sub(self, _: Self) -> Self { Void() }}impl Neg for Void {type Output = Self;fn neg(self) -> Self { Void() }}impl Cost for Void { const MAX: Self = Void(); }// ------------ Graph impl end ------------// ------------ algebraic traits start ------------use std::marker::Sized;use std::ops::*;/// 元pub trait Element: Sized + Clone + PartialEq {}impl<T: Sized + Clone + PartialEq> Element for T {}/// 結合性pub trait Associative: Magma {}/// マグマpub trait Magma: Element + Add<Output=Self> {}impl<T: Element + Add<Output=Self>> Magma for T {}/// 半群pub trait SemiGroup: Magma + Associative {}impl<T: Magma + Associative> SemiGroup for T {}/// モノイドpub trait Monoid: SemiGroup + Zero {}impl<T: SemiGroup + Zero> Monoid for T {}pub trait ComMonoid: Monoid + AddAssign {}impl<T: Monoid + AddAssign> ComMonoid for T {}/// 群pub trait Group: Monoid + Neg<Output=Self> {}impl<T: Monoid + Neg<Output=Self>> Group for T {}pub trait ComGroup: Group + ComMonoid {}impl<T: Group + ComMonoid> ComGroup for T {}/// 半環pub trait SemiRing: ComMonoid + Mul<Output=Self> + One {}impl<T: ComMonoid + Mul<Output=Self> + One> SemiRing for T {}/// 環pub trait Ring: ComGroup + SemiRing {}impl<T: ComGroup + SemiRing> Ring for T {}pub trait ComRing: Ring + MulAssign {}impl<T: Ring + MulAssign> ComRing for T {}/// 体pub trait Field: ComRing + Div<Output=Self> + DivAssign {}impl<T: ComRing + Div<Output=Self> + DivAssign> Field for T {}/// 加法単元pub trait Zero: Element {fn zero() -> Self;fn is_zero(&self) -> bool {*self == Self::zero()}}/// 乗法単元pub trait One: Element {fn one() -> Self;fn is_one(&self) -> bool {*self == Self::one()}}macro_rules! impl_integer {($($T:ty,)*) => {$(impl Associative for $T {}impl Zero for $T {fn zero() -> Self { 0 }fn is_zero(&self) -> bool { *self == 0 }}impl<'a> Zero for &'a $T {fn zero() -> Self { &0 }fn is_zero(&self) -> bool { *self == &0 }}impl One for $T {fn one() -> Self { 1 }fn is_one(&self) -> bool { *self == 1 }}impl<'a> One for &'a $T {fn one() -> Self { &1 }fn is_one(&self) -> bool { *self == &1 }})*};}impl_integer! {i8, i16, i32, i64, i128, isize,u8, u16, u32, u64, u128, usize,}// ------------ algebraic traits end ------------// ------------ FenwickTree with generics start ------------#[derive(Clone, Debug)]pub struct FenwickTree<T>(Vec<T>);impl<T: Monoid> FenwickTree<T> {#[inline]fn lsb(x: usize) -> usize {x & x.wrapping_neg()}pub fn new(n: usize) -> Self {Self(vec![T::zero(); n+1])}pub fn prefix_sum(&self, i: usize) -> T {std::iter::successors(Some(i), |&i| Some(i - Self::lsb(i))).take_while(|&i| i != 0).map(|i| self.0[i].clone()).fold(T::zero(), |sum, x| sum + x)}pub fn add(&mut self, i: usize, x: T) {let n = self.0.len();std::iter::successors(Some(i + 1), |&i| Some(i + Self::lsb(i))).take_while(|&i| i < n).for_each(|i| self.0[i] = self.0[i].clone() + x.clone());}/// pred(j, sum(..j)) && !pred(j+1, sum(..j+1))pub fn partition(&self, pred: impl Fn(usize, &T) -> bool) -> (usize, T) {assert!(pred(0, &self.0[0]), "need to be pred(0, 0)");let mut j = 0;let mut current = self.0[0].clone();let n = self.0.len();for d in std::iter::successors(Some(n.next_power_of_two() >> 1), |&d| { Some(d >> 1)}).take_while(|&d| d != 0){if j + d < n {let next = current.clone() + self.0[j + d].clone();if pred(j + d, &next) {current = next;j += d;}}}(j, current)}}impl<T: Monoid> From<Vec<T>> for FenwickTree<T> {fn from(src: Vec<T>) -> Self {let mut table = std::iter::once(T::zero()).chain(src.into_iter()).collect::<Vec<T>>();let n = table.len();(1..n).map(|i| (i, i + Self::lsb(i))).filter(|&(_, j)| j < n).for_each(|(i, j)| {table[j] = table[j].clone() + table[i].clone();});Self(table)}}impl<T: Group> FenwickTree<T> {pub fn sum<R: RangeBounds<usize>>(&self, rng: R) -> T {let Range { start, end } = bounds_within(rng, self.0.len() - 1);self.prefix_sum(end) + -self.prefix_sum(start)}}// ------------ FenwickTree with generics end ------------use std::ops::Bound::{Excluded, Included, Unbounded};use std::ops::{Range, RangeBounds};/// 区間を配列サイズに収まるように丸める。////// 与えられた区間 `r` と `0..len` の共通部分を、有界な半開区間として返す。////// # Examples/// ```/// use bibliotheca::utils::bounds::bounds_within;////// assert_eq!(bounds_within(.., 7), 0..7);/// assert_eq!(bounds_within(..=4, 7), 0..5);/// ```pub fn bounds_within<R: RangeBounds<usize>>(r: R, len: usize) -> Range<usize> {let e_ex = match r.end_bound() {Included(&e) => e + 1,Excluded(&e) => e,Unbounded => len,}.min(len);let s_in = match r.start_bound() {Included(&s) => s,Excluded(&s) => s + 1,Unbounded => 0,}.min(e_ex);s_in..e_ex}// ------------ io module start ------------use std::io::{stdout, BufWriter, Read, StdoutLock, Write};pub struct IO {iter: std::str::SplitAsciiWhitespace<'static>,buf: BufWriter<StdoutLock<'static>>,}impl IO {pub fn new() -> Self {let mut input = String::new();std::io::stdin().read_to_string(&mut input).unwrap();let input = Box::leak(input.into_boxed_str());let out = Box::new(stdout());IO {iter: input.split_ascii_whitespace(),buf: BufWriter::new(Box::leak(out).lock()),}}fn scan_str(&mut self) -> &'static str {self.iter.next().unwrap()}pub fn scan<T: Scan>(&mut self) -> <T as Scan>::Output {<T as Scan>::scan(self)}pub fn scan_vec<T: Scan>(&mut self, n: usize) -> Vec<<T as Scan>::Output> {(0..n).map(|_| self.scan::<T>()).collect()}pub fn print<T: Print>(&mut self, x: T) {<T as Print>::print(self, x);}pub fn println<T: Print>(&mut self, x: T) {self.print(x);self.print("\n");}pub fn iterln<T: Print, I: Iterator<Item = T>>(&mut self, mut iter: I, delim: &str) {if let Some(v) = iter.next() {self.print(v);for v in iter {self.print(delim);self.print(v);}}self.print("\n");}pub fn flush(&mut self) {self.buf.flush().unwrap();}}impl Default for IO {fn default() -> Self {Self::new()}}pub trait Scan {type Output;fn scan(io: &mut IO) -> Self::Output;}macro_rules! impl_scan {($($t:tt),*) => {$(impl Scan for $t {type Output = Self;fn scan(s: &mut IO) -> Self::Output {s.scan_str().parse().unwrap()}})*};}impl_scan!(i16, i32, i64, isize, u16, u32, u64, usize, String, f32, f64);impl Scan for char {type Output = char;fn scan(s: &mut IO) -> Self::Output {s.scan_str().chars().next().unwrap()}}pub enum Bytes {}impl Scan for Bytes {type Output = &'static [u8];fn scan(s: &mut IO) -> Self::Output {s.scan_str().as_bytes()}}pub enum Chars {}impl Scan for Chars {type Output = Vec<char>;fn scan(s: &mut IO) -> Self::Output {s.scan_str().chars().collect()}}pub enum Usize1 {}impl Scan for Usize1 {type Output = usize;fn scan(s: &mut IO) -> Self::Output {s.scan::<usize>().wrapping_sub(1)}}impl<T: Scan, U: Scan> Scan for (T, U) {type Output = (T::Output, U::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s))}}impl<T: Scan, U: Scan, V: Scan> Scan for (T, U, V) {type Output = (T::Output, U::Output, V::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s), V::scan(s))}}impl<T: Scan, U: Scan, V: Scan, W: Scan> Scan for (T, U, V, W) {type Output = (T::Output, U::Output, V::Output, W::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s), V::scan(s), W::scan(s))}}pub trait Print {fn print(w: &mut IO, x: Self);}macro_rules! impl_print_int {($($t:ty),*) => {$(impl Print for $t {fn print(w: &mut IO, x: Self) {w.buf.write_all(x.to_string().as_bytes()).unwrap();}})*};}impl_print_int!(i16, i32, i64, isize, u16, u32, u64, usize, f32, f64);impl Print for u8 {fn print(w: &mut IO, x: Self) {w.buf.write_all(&[x]).unwrap();}}impl Print for &[u8] {fn print(w: &mut IO, x: Self) {w.buf.write_all(x).unwrap();}}impl Print for &str {fn print(w: &mut IO, x: Self) {w.print(x.as_bytes());}}impl Print for String {fn print(w: &mut IO, x: Self) {w.print(x.as_bytes());}}impl<T: Print, U: Print> Print for (T, U) {fn print(w: &mut IO, (x, y): Self) {w.print(x);w.print(" ");w.print(y);}}impl<T: Print, U: Print, V: Print> Print for (T, U, V) {fn print(w: &mut IO, (x, y, z): Self) {w.print(x);w.print(" ");w.print(y);w.print(" ");w.print(z);}}mod neboccoio_macro {#[macro_export]macro_rules! input {(@start $io:tt @read @rest) => {};(@start $io:tt @read @rest, $($rest: tt)*) => {input!(@start $io @read @rest $($rest)*)};(@start $io:tt @read @rest mut $($rest:tt)*) => {input!(@start $io @read @mut [mut] @rest $($rest)*)};(@start $io:tt @read @rest $($rest:tt)*) => {input!(@start $io @read @mut [] @rest $($rest)*)};(@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: [[$kind:tt; $len1:expr]; $len2:expr] $($rest:tt)*) => {let $($mut)* $var = (0..$len2).map(|_| $io.scan_vec::<$kind>($len1)).collect::<Vec<Vec<$kind>>>();input!(@start $io @read @rest $($rest)*)};(@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: [$kind:tt; $len:expr] $($rest:tt)*) => {let $($mut)* $var = $io.scan_vec::<$kind>($len);input!(@start $io @read @rest $($rest)*)};(@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: $kind:tt $($rest:tt)*) => {let $($mut)* $var = $io.scan::<$kind>();input!(@start $io @read @rest $($rest)*)};(from $io:tt $($rest:tt)*) => {input!(@start $io @read @rest $($rest)*)};}}// ------------ io module end ------------