Why I am Getting TLE?

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1

I watched the video editorial of FLGZRO and tried to implement the solution. But I am getting TLE. Could someone please point out any optimization?

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

#define ll long long
#define endl "\n"
const int M = 1e9+7;

vector<int> graph[100001];
ll in[100001], ans[100001], subtree[100001], a[100001];
map<ll,vector<int>> aval;
int timer;

void dfs(int node, int par){
    ans[node] = 0;
    subtree[node] = 0;
    in[node] = timer++;
    for(auto child:graph[node]){
        if(child==par)continue;
        dfs(child,node);
        ans[node] += subtree[child];
        subtree[node] += subtree[child];
        ans[node] %= M;
        subtree[node] %= M;
    }
    if(ans[node]==0){
        ans[node] = 1;
        subtree[node] = 1;
    }
    else{
        for(auto it: aval[a[node]]){
            if(in[node]<in[it]){
                ans[node] += (M - ans[it]);
                ans[node] %= M;
            }
        }
        subtree[node] += ans[node];
        subtree[node] %= M;
    }
    aval[a[node]].push_back(node);    
}

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int t; cin>>t;
    while(t--){
        int n; cin>>n;
        timer = 1;
        for(int i = 0; i <n -1; i++){
            int u,v;
            cin>>u>>v;
            graph[u].push_back(v);
            graph[v].push_back(u);
        }
        
        for(int i =1; i  <=n; i++)cin>>a[i];
        if(n==1){
            cout<<1<<endl;
            continue;
        }
        dfs(1,-1);
        cout<<subtree[1]<<endl;
        for(int i = 0; i <=n; i++){
            graph[i].clear();
            in[i] = 0;
        }
        aval.clear();
    }
    return 0;
}