For problem statement at 0-999/300-399/370-379/375/problemD.txt this is a correct solution, but verifier at 0-999/300-399/370-379/375/verifierD.go ends with All tests passed can you fix the verifier? package main

import (
	"bufio"
	"fmt"
	"os"
)

var adj [][]int
var col []int
var sz []int
var color_freq []int
var query_per_node [][]struct{ idx, k int }
var answer []int
var ft *Fenwick
var n int

type Fenwick struct {
	tree []int
	n    int
}

func NewFenwick(n int) *Fenwick {
	return &Fenwick{n: n, tree: make([]int, n+2)}
}

func (f *Fenwick) update(idx int, val int) {
	for idx <= f.n {
		f.tree[idx] += val
		idx += idx & -idx
	}
}

func (f *Fenwick) query(idx int) int {
	if idx > f.n {
		idx = f.n
	}
	sum := 0
	for idx > 0 {
		sum += f.tree[idx]
		idx -= idx & -idx
	}
	return sum
}

func (f *Fenwick) rangeQuery(l, r int) int {
	if l > r {
		return 0
	}
	return f.query(r) - f.query(l-1)
}

func add(c int) {
	old := color_freq[c]
	color_freq[c]++
	nw := old + 1
	if old == 0 {
		ft.update(1, 1)
	} else {
		ft.update(old, -1)
		ft.update(nw, 1)
	}
}

func remove(c int) {
	old := color_freq[c]
	color_freq[c]--
	nw := old - 1
	if nw == 0 {
		ft.update(old, -1)
	} else {
		ft.update(old, -1)
		ft.update(nw, 1)
	}
}

func add_tree(u, par int) {
	add(col[u])
	for _, v := range adj[u] {
		if v != par {
			add_tree(v, u)
		}
	}
}

func remove_tree(u, par int) {
	remove(col[u])
	for _, v := range adj[u] {
		if v != par {
			remove_tree(v, u)
		}
	}
}

func getsz(u, par int) {
	sz[u] = 1
	for _, v := range adj[u] {
		if v != par {
			getsz(v, u)
			sz[u] += sz[v]
		}
	}
}

func dsu_dfs(u, par int, keep bool) {
	heavy := -1
	maxsz := -1
	for _, v := range adj[u] {
		if v != par && sz[v] > maxsz {
			maxsz = sz[v]
			heavy = v
		}
	}
	for _, v := range adj[u] {
		if v != par && v != heavy {
			dsu_dfs(v, u, false)
		}
	}
	if heavy != -1 {
		dsu_dfs(heavy, u, true)
	}
	for _, v := range adj[u] {
		if v != par && v != heavy {
			add_tree(v, u)
		}
	}
	add(col[u])
	for _, q := range query_per_node[u] {
		k := q.k
		res := ft.rangeQuery(k, n)
		answer[q.idx] = res
	}
	if !keep {
		remove_tree(u, par)
	}
}

func main() {
	in := bufio.NewReader(os.Stdin)
	fmt.Fscan(in, &n)
	var m int
	fmt.Fscan(in, &m)
	answer = make([]int, m)
	col = make([]int, n+1)
	for i := 1; i <= n; i++ {
		fmt.Fscan(in, &col[i])
	}
	adj = make([][]int, n+1)
	for i := 0; i < n-1; i++ {
		var a, b int
		fmt.Fscan(in, &a, &b)
		adj[a] = append(adj[a], b)
		adj[b] = append(adj[b], a)
	}
	query_per_node = make([][]struct{ idx, k int }, n+1)
	for i := 0; i < m; i++ {
		var v, k int
		fmt.Fscan(in, &v, &k)
		query_per_node[v] = append(query_per_node[v], struct{ idx, k int }{i, k})
	}
	sz = make([]int, n+1)
	getsz(1, -1)
	color_freq = make([]int, 100010)
	ft = NewFenwick(n)
	dsu_dfs(1, -1, false)
	for _, ans := range answer {
		fmt.Println(ans)
	}
}