思路：
這個DFS序還是蠻有意思的~然後就可以把以u為根的樹的狀態直接轉化到區間（一維陣列）上，而且陣列是不大的。
然後就變成了區間處理，套一下莫隊就好了。
Code:

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;

#define mem(a, b) memset(a, b, sizeof(a))
const int Maxn = 1e5 + 10;
struct Edge{int v, nex;}edge[Maxn<<1];
int head[Maxn], tol;
void
 
 init(){tol = 0,mem(head, -1);}
void addedge(int u, int v){
    edge[tol] = (Edge){v, head[u]}, head[u] = tol++;
    edge[tol] = (Edge){u, head[v]}, head[v] = tol++;
}

int w[Maxn], _time, val[Maxn], n, k, q, a[Maxn];
int Left[Maxn], Right[Maxn];
vector<int>xs;
struct asd{
    int id;
    int Left, Right;
}node[Maxn];
int
 
 res[Maxn], ans, sum[Maxn];
int pos[Maxn];
bool cmp(asd x,asd y)
{
    if(pos[x.Left] == pos[y.Left])
        return x.Right<y.Right;
    return pos[x.Left]<pos[y.Left];
}

void DFS(int u, int fa){
    int v;
    Left[u] = ++_time, w[_time] = a[u];
    for(int i=head[u]; ~i;i = edge[i].nex){
        v = edge[i].v;
        if
 
(v == fa) continue;
        DFS(v, u);
    }
    Right[u] = _time;
}

void ADD(int ww){
    if(sum[ww] == k) ans--;
    sum[ww]++;
    if(sum[ww] == k) ans++;
}
void DEL(int ww){
    if(sum[ww] == k) ans--;
    sum[ww]--;
    if(sum[ww] == k) ans++;
}

void solve(){
    ans=0;
    mem(sum, 0);
    sort(node+1, node+1+q, cmp);
    for(int i=node[1].Left;i<=node[1].Right;i++){
        ADD(w[i]);
    }
    res[node[1].id]=ans;
    int L=node[1].Left,R=node[1].Right;
    for(int i=2; i<=q; i++){
        while(R<node[i].Right){
            R++;
            ADD(w[R]);
        }
        while(R>node[i].Right){
            DEL(w[R]);
            R--;
        }
        while(L<node[i].Left){
            DEL(w[L]);
            L++;
        }
        while(L>node[i].Left){
            L--;
            ADD(w[L]);
        }
        res[node[i].id]=ans;
    }
    for(int i=1;i<=q;i++)
        printf("%d\n", res[i]);
}


int main()
{
    int T, u, v, L, R;
    scanf("%d", &T);
    for(int cas = 1; cas <= T; cas++){
        scanf("%d%d",&n, &k);
        xs.clear();
        int block=(int)sqrt(n);
        for(int i=1;i<=n;i++){
            scanf("%d", &a[i]);
            xs.push_back(a[i]);
            pos[i]=(i-1)/block+1;
        }
        sort(xs.begin(), xs.end());
        xs.erase(unique(xs.begin(), xs.end()), xs.end());
        for(int i=1;i<=n;++i) a[i] = lower_bound(xs.begin(), xs.end(), a[i]) - xs.begin() + 1;

        init();
        for(int i=1;i<n;i++){
            scanf("%d%d", &u, &v);
            addedge(u, v);
        }
        _time = 0;
        DFS(1, -1);

        scanf("%d", &q);
        for(int i=1;i<=q;i++){
            scanf("%d", &u);
            node[i].id = i;
            node[i].Left = Left[u], node[i].Right = Right[u];
        }
        printf("Case #%d:\n", cas);
        solve();
        if(cas != T) puts("");
    }
    return 0;
}