#[allow(unused_imports)] #[cfg(feature = "dbg")] use dbg::lg; use { make_graph::tuple_make_undirected, sort_tree::sort_tree, std::{ iter::repeat_with, ptr::{self, null_mut}, }, }; fn main() { let mut buf = ngtio::with_stdin(); let n = buf.usize(); let g = tuple_make_undirected( n, &repeat_with(|| (buf.usize() - 1, buf.usize() - 1)) .take(n - 1) .collect::>(), ); let [_, parent] = sort_tree(0, &g); let mut lct = LinkCutTree::new(n); for (i, &p) in parent.iter().enumerate() { if i != p { lct.link(i, p); } } for _ in 0..buf.usize() { let u = buf.usize() - 1; let v = buf.usize() - 1; let q = lct.lca(u, v).unwrap(); lct.act_from_root(u, 1); lct.act_from_root(v, 1); lct.act_from_root(q, -1); if let Some(q) = lct.parent(q) { lct.act_from_root(q, -1); } } let ans = (0..n) .map(|i| lct.value(i) as i64) .map(|x| x * (x + 1) / 2) .sum::(); println!("{}", ans); } pub struct LinkCutTree { nodes: Vec<*mut Node>, } impl LinkCutTree { pub fn new(len: usize) -> Self { let nodes = (0..len) .map(|id| Box::into_raw(Box::new(Node::new(id)))) .collect::>(); Self { nodes } } pub fn is_empty(&self) -> bool { self.nodes.is_empty() } pub fn len(&self) -> usize { self.nodes.len() } /// 頂点 `child` が根でないとき親の ID を返し、そうでないとき `None` を /// 返します。 /// /// # Panics /// /// - `child` が `self.len()` 以上のとき /// pub fn parent(&self, child: usize) -> Option { let child = self.__index(child); unsafe { expose(child); let l = (*child).left; l.as_ref().map(|l| l.id) } } /// 頂点 `u`, `v` が同じ木に属するとき、`true` /// /// # Panics /// /// - `u`, `v` のいずれかが `self.len()` 以上のとき /// pub fn same(&self, u: usize, v: usize) -> bool { let u = self.__index(u); let v = self.__index(v); unsafe { expose(u); expose(v); ptr::eq(u, v) || !(*u).parent.is_null() } } /// ある木の根 `child` を別の木の頂点 `parent` の子にします。 /// /// # Panics /// /// - `child`, `parent` のいずれかが `self.len()` 以上のとき /// - `child` と `parent` が同じ木に属するとき /// - `child` が根でないとき /// pub fn link(&mut self, child: usize, parent: usize) { debug_assert!(!self.same(child, parent)); let child = self.__index(child); let parent = self.__index(parent); unsafe { (*child).parent = parent } } /// 根でない頂点 `child` と、その親を結ぶ辺を消去し、もともと /// 親だった頂点の ID を返します。 /// /// # Panics /// /// - `child` が `self.len()` 以上のとき /// - `child` がある頂点の値であるとき /// pub fn cut(&mut self, child: usize) -> usize { debug_assert!(child < self.nodes.len()); let child = self.nodes[child]; unsafe { expose(child); let l = (*child).left; debug_assert!(!l.is_null()); (*l).parent = null_mut(); (*child).left = null_mut(); (*child).update(); (&*l).id } } /// 頂点 `u` と `v` が同じ木に属するとき LCA を返し、そうでないとき /// `None` を返します。 /// /// # Panics /// /// - `u`, `v` のいずれかが `self.len()` 以上のとき /// pub fn lca(&self, u: usize, v: usize) -> Option { let u = self.__index(u); let v = self.__index(v); unsafe { expose(u); expose(v).as_ref().map(|q| q.id) } } pub fn depth(&self, _u: usize) -> usize { todo!() } pub fn act_from_root(&mut self, u: usize, lazy: i32) { let u = self.__index(u); unsafe { expose(u); (*u).lazy += lazy; (*u).push(); } } pub fn value(&self, u: usize) -> i32 { let u = self.__index(u); unsafe { expose(u); (&*u).value } } fn __index(&self, index: usize) -> *mut Node { if self.nodes.len() <= index { panic!( "index {} out of range for link-cut tree of length {}", index, self.len(), ); } self.nodes[index] } } unsafe fn expose(v: *mut Node) -> *mut Node { let mut last = null_mut(); let mut now = v; while !now.is_null() { (*now).splay(); (*now).right = last; last = now; now = (*now).parent; } (*v).splay(); last } struct Node { left: *mut Node, right: *mut Node, parent: *mut Node, id: usize, lazy: i32, value: i32, } impl Node { fn new(id: usize) -> Self { Self { left: null_mut(), right: null_mut(), parent: null_mut(), id, value: 0, lazy: 0, } } unsafe fn rotate(&mut self) { let p = self.parent; let pp = (*p).parent; let c; if ptr::eq((*p).left, self) { c = self.right; self.right = p; (*p).left = c; } else { c = self.left; self.left = p; (*p).right = c; } if !pp.is_null() && ptr::eq((*pp).left, p) { (*pp).left = self; } if !pp.is_null() && ptr::eq((*pp).right, p) { (*pp).right = self; } self.parent = pp; (*p).parent = self; if !c.is_null() { (*c).parent = p; } (*p).update(); self.update(); } unsafe fn splay(&mut self) { while self.state() != 0 { let p = self.parent; if (*p).state() == 0 { (*p).push(); self.push(); self.rotate(); } else { let g = (*p).parent; (*g).push(); (*p).push(); self.push(); if self.state() == (*p).state() { (*p).rotate(); self.rotate(); } else { self.rotate(); self.rotate(); } } } self.push(); } unsafe fn state(&self) -> i8 { if self.parent.is_null() { 0 } else if ptr::eq((*self.parent).left, self) { 1 } else if ptr::eq((*self.parent).right, self) { -1 } else { 0 } } unsafe fn update(&mut self) {} unsafe fn push(&mut self) { if self.lazy != 0 { if let Some(l) = self.left.as_mut() { l.lazy += self.lazy; } if let Some(r) = self.right.as_mut() { r.lazy += self.lazy; } self.value += self.lazy; self.lazy = 0; } } } // sort_tree {{{ #[allow(dead_code)] mod sort_tree { pub fn remove_parent(g: &mut [Vec], parent: &[usize]) { g.iter_mut().enumerate().for_each(|(x, gx)| { if let Some(i) = gx.iter().position(|&y| y == parent[x]) { gx.swap_remove(i); }; }); } pub fn sort_tree_remove_parent(root: usize, g: &mut [Vec]) -> [Vec; 2] { let [ord, parent] = sort_tree(root, g); remove_parent(g, &parent); [ord, parent] } pub fn sort_tree(root: usize, g: &[Vec]) -> [Vec; 2] { sort_tree_by(root, g, |x| *x) } pub fn sort_tree_by(root: usize, g: &[Vec], to: impl Fn(&E) -> usize) -> [Vec; 2] { let mut ord = Vec::new(); let mut parent = vec![root; g.len()]; sort_tree_impl(root, root, g, &to, &mut parent, &mut ord); [ord, parent] } fn sort_tree_impl( x: usize, p: usize, g: &[Vec], to: &impl Fn(&E) -> usize, parent: &mut [usize], ord: &mut Vec, ) { ord.push(x); parent[x] = p; g[x].iter() .map(to) .filter(|&y| y != p) .for_each(|y| sort_tree_impl(y, x, g, to, parent, ord)) } } // }}} // make_graph {{{ #[allow(dead_code)] mod make_graph { pub fn tuple_make_undirected(n: usize, edges: &[(usize, usize)]) -> Vec> { make_undirected_by(n, edges, |&(u, v)| [u, v]) } pub fn array_make_undirected(n: usize, edges: &[[usize; 2]]) -> Vec> { make_undirected_by(n, edges, |&[u, v]| [u, v]) } pub fn make_undirected_by( n: usize, edges: &[E], f: impl Fn(&E) -> [usize; 2], ) -> Vec> { let mut g = vec![Vec::new(); n]; for [u, v] in edges.iter().map(f) { g[u].push(v); g[v].push(u); } g } pub fn tuple_make_directed(n: usize, edges: &[(usize, usize)]) -> Vec> { make_directed_by(n, edges, |&(u, v)| [u, v]) } pub fn array_make_directed(n: usize, edges: &[[usize; 2]]) -> Vec> { make_directed_by(n, edges, |&[u, v]| [u, v]) } pub fn make_directed_by( n: usize, edges: &[E], f: impl Fn(&E) -> [usize; 2], ) -> Vec> { let mut g = vec![Vec::new(); n]; edges.iter().map(f).for_each(|[u, v]| g[u].push(v)); g } pub fn tuple_make_undirected_weighted( n: usize, edges: &[(usize, usize, T)], ) -> Vec> { make_undirected_weighted_by(n, edges, |&(u, v, x)| ([u, v], x)) } pub fn array_make_undirected_weighted( n: usize, edges: &[([usize; 2], T)], ) -> Vec> { make_undirected_weighted_by(n, edges, |&([u, v], x)| ([u, v], x)) } pub fn make_undirected_weighted_by( n: usize, edges: &[E], f: impl Fn(&E) -> ([usize; 2], T), ) -> Vec> { let mut g = vec![Vec::new(); n]; for ([u, v], x) in edges.iter().map(f) { g[u].push((v, x)); g[v].push((u, x)); } g } pub fn tuple_make_directed_weighted( n: usize, edges: &[(usize, usize, T)], ) -> Vec> { make_directed_weighted_by(n, edges, |&(u, v, x)| ([u, v], x)) } pub fn array_make_directed_weighted( n: usize, edges: &[([usize; 2], T)], ) -> Vec> { make_directed_weighted_by(n, edges, |&([u, v], x)| ([u, v], x)) } pub fn make_directed_weighted_by( n: usize, edges: &[E], f: impl Fn(&E) -> ([usize; 2], T), ) -> Vec> { let mut g = vec![Vec::new(); n]; edges .iter() .map(f) .for_each(|([u, v], w)| g[u].push((v, w))); g } } // }}} // template {{{ #[cfg(not(feature = "dbg"))] #[allow(unused_macros)] #[macro_export] macro_rules! lg { ($($expr:expr),*) => {}; } #[allow(dead_code)] mod ngtio { mod i { pub use self::{ multi_token::{Leaf, Parser, ParserTuple, RawTuple, Tuple, VecLen}, token::{Token, Usize1}, }; use std::{ io::{self, BufRead}, iter, }; pub fn with_stdin() -> Tokenizer> { io::BufReader::new(io::stdin()).tokenizer() } pub fn with_str(src: &str) -> Tokenizer<&[u8]> { src.as_bytes().tokenizer() } pub struct Tokenizer { queue: Vec, // FIXME: String のみにすると速そうです。 scanner: S, } macro_rules! prim_method { ($name:ident: $T:ty) => { pub fn $name(&mut self) -> $T { <$T>::leaf().parse(self) } }; ($name:ident) => { prim_method!($name: $name); }; } macro_rules! prim_methods { ($name:ident: $T:ty; $($rest:tt)*) => { prim_method!($name:$T); prim_methods!($($rest)*); }; ($name:ident; $($rest:tt)*) => { prim_method!($name); prim_methods!($($rest)*); }; () => () } impl Tokenizer { pub fn token(&mut self) -> String { self.load(); self.queue.pop().expect("入力が終了したのですが。") } pub fn new(scanner: S) -> Self { Self { queue: Vec::new(), scanner, } } fn load(&mut self) { while self.queue.is_empty() { let mut s = String::new(); let length = self.scanner.read_line(&mut s).unwrap(); // 入力が UTF-8 でないときにエラーだそうです。 if length == 0 { break; } self.queue = s.split_whitespace().rev().map(str::to_owned).collect(); } } pub fn skip_line(&mut self) { assert!( self.queue.is_empty(), "行の途中で呼ばないでいただきたいです。現在のトークンキュー: {:?}", &self.queue ); self.load(); } pub fn end(&mut self) { self.load(); assert!(self.queue.is_empty(), "入力はまだあります!"); } pub fn parse(&mut self) -> T::Output { T::parse(&self.token()) } pub fn parse_collect(&mut self, n: usize) -> B where B: iter::FromIterator, { iter::repeat_with(|| self.parse::()).take(n).collect() } pub fn tuple(&mut self) -> ::Output { T::leaf_tuple().parse(self) } pub fn vec(&mut self, len: usize) -> Vec { T::leaf().vec(len).parse(self) } pub fn vec_tuple( &mut self, len: usize, ) -> Vec<::Output> { T::leaf_tuple().vec(len).parse(self) } pub fn vec2(&mut self, height: usize, width: usize) -> Vec> { T::leaf().vec(width).vec(height).parse(self) } pub fn vec2_tuple( &mut self, height: usize, width: usize, ) -> Vec::Output>> where T: RawTuple, { T::leaf_tuple().vec(width).vec(height).parse(self) } prim_methods! { u8; u16; u32; u64; u128; usize; i8; i16; i32; i64; i128; isize; f32; f64; char; string: String; } } mod token { use super::multi_token::Leaf; use std::{any, fmt, marker, str}; pub trait Token: Sized { type Output; fn parse(s: &str) -> Self::Output; fn leaf() -> Leaf { Leaf(marker::PhantomData) } } impl Token for T where T: str::FromStr, ::Err: fmt::Debug, { type Output = Self; fn parse(s: &str) -> Self::Output { s.parse().unwrap_or_else(|_| { panic!("Parse error!: ({}: {})", s, any::type_name::(),) }) } } pub struct Usize1 {} impl Token for Usize1 { type Output = usize; fn parse(s: &str) -> Self::Output { usize::parse(s) .checked_sub(1) .expect("Parse error! (Zero substruction error of Usize1)") } } } mod multi_token { use super::{Token, Tokenizer}; use std::{io::BufRead, iter, marker}; pub trait Parser: Sized { type Output; fn parse(&self, server: &mut Tokenizer) -> Self::Output; fn vec(self, len: usize) -> VecLen { VecLen { len, elem: self } } } pub struct Leaf(pub(super) marker::PhantomData); impl Parser for Leaf { type Output = T::Output; fn parse(&self, server: &mut Tokenizer) -> T::Output { server.parse::() } } pub struct VecLen { pub len: usize, pub elem: T, } impl Parser for VecLen { type Output = Vec; fn parse(&self, server: &mut Tokenizer) -> Self::Output { iter::repeat_with(|| self.elem.parse(server)) .take(self.len) .collect() } } pub trait RawTuple { type LeafTuple: Parser; fn leaf_tuple() -> Self::LeafTuple; } pub trait ParserTuple { type Tuple: Parser; fn tuple(self) -> Self::Tuple; } pub struct Tuple(pub T); macro_rules! impl_tuple { ($($t:ident: $T:ident),*) => { impl<$($T),*> Parser for Tuple<($($T,)*)> where $($T: Parser,)* { type Output = ($($T::Output,)*); #[allow(unused_variables)] fn parse(&self, server: &mut Tokenizer) -> Self::Output { match self { Tuple(($($t,)*)) => { ($($t.parse(server),)*) } } } } impl<$($T: Token),*> RawTuple for ($($T,)*) { type LeafTuple = Tuple<($(Leaf<$T>,)*)>; fn leaf_tuple() -> Self::LeafTuple { Tuple(($($T::leaf(),)*)) } } impl<$($T: Parser),*> ParserTuple for ($($T,)*) { type Tuple = Tuple<($($T,)*)>; fn tuple(self) -> Self::Tuple { Tuple(self) } } }; } impl_tuple!(); impl_tuple!(t1: T1); impl_tuple!(t1: T1, t2: T2); impl_tuple!(t1: T1, t2: T2, t3: T3); impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4); impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5); impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6); impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7); impl_tuple!( t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8 ); } trait Scanner: BufRead + Sized { fn tokenizer(self) -> Tokenizer { Tokenizer::new(self) } } impl Scanner for R {} } pub use self::i::{with_stdin, with_str}; mod prelude { pub use super::i::{Parser, ParserTuple, RawTuple, Token, Usize1}; } } // }}}