package contest; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.InputMismatchException; public class Q1024 { InputStream is; PrintWriter out; String INPUT = ""; void solve() { int n = ni(); if(!(n >= 2))throw new AssertionError(); if(!(n <= 100000))throw new AssertionError(); int[] a = na(n); for(int i = 0;i < n;i++){ if(!(a[i] >= 1))throw new AssertionError(); if(!(a[i] <= 100000))throw new AssertionError(); } DJSet ds = new DJSet(n); int[] from = new int[n - 1]; int[] to = new int[n - 1]; for (int i = 0; i < n - 1; i++) { from[i] = ni() - 1; to[i] = ni() - 1; ds.union(from[i], to[i]); } if(!(ds.count() == 1))throw new AssertionError(); int[][] g = packU(n, from, to); int[][] pars = parents3(g, 0); int[] par = pars[0], ord = pars[1], dep = pars[2]; int[][] spar = logstepParents(par); int[] lim = new int[n]; Arrays.fill(lim, -1); for(int i = 0;i < n;i++){ int cur = ord[i]; if(cur == 0){ lim[cur] = 0; }else if(lim[par[cur]] == par[cur]){ lim[cur] = a[cur] == a[par[cur]] ? cur : par[cur]; }else{ int u = a[cur], v = a[par[cur]], w = a[par[par[cur]]]; if(kadomatu(u, v, w)){ lim[cur] = lim[par[cur]]; }else if(u != v){ lim[cur] = par[cur]; }else{ lim[cur] = cur; } } } for(int Q = ni();Q > 0;Q--){ int u = ni()-1, v = ni()-1; int lca = lca2(u, v, spar, dep); // period <= 2 if(dep[u]+dep[v]-2*dep[lca] <= 1){ out.println("NO"); continue; } if(!(dep[lim[u]] <= dep[lca] && dep[lim[v]] <= dep[lca])){ out.println("NO"); continue; } if(u != lca && v != lca && !kadomatu(a[ancestor(u, dep[u]-dep[lca]-1, spar)], a[lca], a[ancestor(v, dep[v]-dep[lca]-1, spar)])){ out.println("NO"); continue; } if(v != lca && !kadomatu(a[u], a[v], a[par[v]])){ out.println("NO"); continue; } if(u != lca && !kadomatu(a[par[u]], a[u], a[v])){ out.println("NO"); continue; } if(v == lca && !kadomatu(a[u], a[v], a[ancestor(u, dep[u]-dep[lca]-1, spar)])){ out.println("NO"); continue; } if(u == lca && !kadomatu(a[ancestor(v, dep[v]-dep[lca]-1, spar)], a[u], a[v])){ out.println("NO"); continue; } out.println("YES"); } } static boolean kadomatu(int u, int v, int w) { return u != v && v != w && w != u && (u < v && v > w || u > v && v < w); } public static int lca2(int a, int b, int[][] spar, int[] depth) { if (depth[a] < depth[b]) { b = ancestor(b, depth[b] - depth[a], spar); } else if (depth[a] > depth[b]) { a = ancestor(a, depth[a] - depth[b], spar); } if (a == b) return a; int sa = a, sb = b; for (int low = 0, high = depth[a], t = Integer.highestOneBit(high), k = Integer .numberOfTrailingZeros(t); t > 0; t >>>= 1, k--) { if ((low ^ high) >= t) { if (spar[k][sa] != spar[k][sb]) { low |= t; sa = spar[k][sa]; sb = spar[k][sb]; } else { high = low | t - 1; } } } return spar[0][sa]; } protected static int ancestor(int a, int m, int[][] spar) { for (int i = 0; m > 0 && a != -1; m >>>= 1, i++) { if ((m & 1) == 1) a = spar[i][a]; } return a; } public static class DJSet { public int[] upper; public DJSet(int n) { upper = new int[n]; Arrays.fill(upper, -1); } public int root(int x) { return upper[x] < 0 ? x : (upper[x] = root(upper[x])); } public boolean equiv(int x, int y) { return root(x) == root(y); } public boolean union(int x, int y) { x = root(x); y = root(y); if (x != y) { if (upper[y] < upper[x]) { int d = x; x = y; y = d; } upper[x] += upper[y]; upper[y] = x; } return x == y; } public int count() { int ct = 0; for (int u : upper) if (u < 0) ct++; return ct; } } public static int[][] logstepParents(int[] par) { int n = par.length; int m = Integer.numberOfTrailingZeros(Integer.highestOneBit(n - 1)) + 1; int[][] pars = new int[m][n]; pars[0] = par; for (int j = 1; j < m; j++) { for (int i = 0; i < n; i++) { pars[j][i] = pars[j - 1][i] == -1 ? -1 : pars[j - 1][pars[j - 1][i]]; } } return pars; } public static int[][] parents3(int[][] g, int root) { int n = g.length; int[] par = new int[n]; Arrays.fill(par, -1); int[] depth = new int[n]; depth[0] = 0; int[] q = new int[n]; q[0] = root; for (int p = 0, r = 1; p < r; p++) { int cur = q[p]; for (int nex : g[cur]) { if (par[cur] != nex) { q[r++] = nex; par[nex] = cur; depth[nex] = depth[cur] + 1; } } } return new int[][] { par, q, depth }; } static int[][] packU(int n, int[] from, int[] to) { int[][] g = new int[n][]; int[] p = new int[n]; for (int f : from) p[f]++; for (int t : to) p[t]++; for (int i = 0; i < n; i++) g[i] = new int[p[i]]; for (int i = 0; i < from.length; i++) { g[from[i]][--p[from[i]]] = to[i]; g[to[i]][--p[to[i]]] = from[i]; } return g; } void run() throws Exception { is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); } public static void main(String[] args) throws Exception { new Q1024().run(); } private byte[] inbuf = new byte[1024]; private int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private int ni() { int num = 0, b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); } }