use std::io::{Write, BufWriter}; // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { ($($r:tt)*) => { let stdin = std::io::stdin(); let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock())); let mut next = move || -> String{ bytes.by_ref().map(|r|r.unwrap() as char) .skip_while(|c|c.is_whitespace()) .take_while(|c|!c.is_whitespace()) .collect() }; input_inner!{next, $($r)*} }; } macro_rules! input_inner { ($next:expr) => {}; ($next:expr,) => {}; ($next:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($next, $t); input_inner!{$next $($r)*} }; } macro_rules! read_value { ($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, usize1) => (read_value!($next, usize) - 1); ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error")); } /// Lowest Common Ancestor. Call lca(x, y) to get the lca of them. /// Many-rooted version. /// Verified by: https://yukicoder.me/submissions/413634 pub struct LCA { n: usize, bn: usize, parent: Vec, // r is root <=> parent[r] = r dep: Vec, lca_tbl: Vec> } impl LCA { fn dfs(&mut self, edges: &[Vec], v: usize, par: usize, d: usize) { self.parent[v] = par; self.dep[v] = d; for &u in edges[v].iter() { if u != par { self.dfs(edges, u, v, d + 1); } } } fn lca_init(&mut self) { let n = self.n; for v in 0 .. n { self.lca_tbl[v] = vec![0; self.bn + 1]; self.lca_tbl[v][0] = self.parent[v]; } for i in 1..self.bn + 1 { for v in 0..n { self.lca_tbl[v][i] = self.lca_tbl[self.lca_tbl[v][i - 1]][i - 1]; } } } pub fn lca(&self, mut x: usize, mut y: usize) -> usize { let dx = self.dep[x]; let mut dy = self.dep[y]; if dx > dy { return self.lca(y, x); } for l in (0..self.bn + 1).rev() { if dy - dx >= 1 << l { y = self.lca_tbl[y][l]; dy -= 1 << l; } } assert_eq!(dx, dy); if x == y { return x; } for l in (0..self.bn + 1).rev() { if self.lca_tbl[x][l] != self.lca_tbl[y][l] { x = self.lca_tbl[x][l]; y = self.lca_tbl[y][l]; } } self.lca_tbl[x][0] } #[allow(unused)] pub fn depth(&self, a: usize) -> usize { self.dep[a] } #[allow(unused)] pub fn parent(&self, a: usize) -> usize { self.parent[a] } #[allow(unused)] fn child(&self, anc: usize, des: usize) -> usize { let x = self.dep[des] - self.dep[anc] - 1; let mut ans = des; for i in 0..self.bn + 1 { if (x & 1 << i) != 0 { ans = self.lca_tbl[ans][i]; } } ans } pub fn new(edges: &[Vec], roots: &[usize]) -> Self { let n = edges.len(); let bn = (n.next_power_of_two() - 1).count_ones() as usize; let mut ret = LCA { n: n, bn: bn, parent: vec![0; n], dep: vec![0; n], lca_tbl: vec![Vec::new(); n] }; for &r in roots { ret.dfs(edges, r, r, 0); } ret.lca_init(); ret } } fn main() { // In order to avoid potential stack overflow, spawn a new thread. let stack_size = 104_857_600; // 100 MB let thd = std::thread::Builder::new().stack_size(stack_size); thd.spawn(|| solve()).unwrap().join().unwrap(); } fn dfs(v: usize, par: usize, gpar: usize, a: &[i64], g: &[Vec], dp1: &mut [i32], dp2: &mut [i32], dpeq: &mut [i32], x1: i32, x2: i32, xeq: i32) { let n = g.len(); let a1 = if par == n || a[par] > a[v] { 0 } else { 1 }; let a2 = if par == n || a[par] < a[v] { 0 } else { 1 }; let aeq = if gpar == n || a[gpar] != a[v] { 0 } else { 1 }; dp1[v] = x1 + a1; dp2[v] = x2 + a2; dpeq[v] = xeq + aeq; for &w in &g[v] { if par == w { continue; } dfs(w, v, par, a, g, dp1, dp2, dpeq, x2 + a2, x1 + a1, xeq + aeq); } } fn solve() { let out = std::io::stdout(); let mut out = BufWriter::new(out.lock()); macro_rules! puts {($($format:tt)*) => (let _ = write!(out,$($format)*););} input! { n: usize, a: [i64; n], xy: [(usize1, usize1); n - 1], q: usize, uv: [(usize1, usize1); q], } let mut g = vec![vec![]; n]; for &(x, y) in &xy { g[x].push(y); g[y].push(x); } let lca = LCA::new(&g, &[0]); let mut dp1 = vec![0; n]; let mut dp2 = vec![0; n]; let mut dpeq = vec![0; n]; dfs(0, n, n, &a, &g, &mut dp1, &mut dp2, &mut dpeq, 0, 0, 0); let ac = |anc: usize, ch: usize, des: usize| -> bool { let x = lca.dep[des] - lca.dep[anc]; dpeq[des] == dpeq[ch] && if x % 2 == 0 { dp1[des] == dp1[anc] || dp2[des] == dp2[anc] } else { dp1[des] == dp2[anc] || dp2[des] == dp1[anc] } }; let is_kado = |v: usize, x: usize, y: usize| { a[x] != a[y] && (a[x] - a[v]) * (a[y] - a[v]) > 0 }; for &(u, v) in &uv { let l = lca.lca(u, v); let (mut ok, x, y) = if u == l || v == l { let other = u + v - l; let ch = lca.child(l, other); let par = lca.parent[other]; if par == l { (false, 0, 0) } else if u == l { (ac(l, ch, other), ch, par) } else { (ac(l, ch, other), par, ch) } } else { let chu = lca.child(l, u); let chv = lca.child(l, v); let is_kado = is_kado(l, chu, chv); (ac(l, chu, u) && ac(l, chv, v) && is_kado, lca.parent[u], lca.parent[v]) }; if ok { if !is_kado(u, x, v) || !is_kado(v, y, u) { ok = false; } } puts!("{}\n", if ok { "YES" } else { "NO" }); } }