SPOJ数据能下载吗？SIGFPE求调

#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
const int MAXN=1e5+5,MAXNUM=1300000;
int n;
vector<int>prime;
bool vis[MAXNUM];
class TREE{
private:
    int sz[MAXN],maxson[MAXN];
    vector<int>g[MAXN];
    void init(){
        centroid[0]=centroid[1]=-1;
        for(int i=1;i<=n;i++){
            g[i].clear();
        }
    }
    ull hsh[MAXN];
    void gethash(int x,int fa){
        hsh[x]=1;
        sz[x]=1;
        for(auto it:g[x]){
            if(it==fa) continue;
            gethash(it,x);
            hsh[x]+=hsh[it]*(ull)prime[sz[it]];
            sz[x]+=sz[it];
        }
    }
public:
    void buildtree(){
        init();
        for(int i=1,u,v;i<n;i++){
            cin>>u>>v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
    }
    int centroid[2];
    void getcentroid(int x,int fa){
        sz[x]=1;
        maxson[x]=0;
        for(auto it:g[x]){
            if(it==fa) continue;
            getcentroid(it,x);
            maxson[x]=max(maxson[x],sz[it]);
            sz[x]+=sz[it];
        }
        maxson[x]=max(maxson[x],n-sz[x]);
        if(maxson[x]<=n/2)
            centroid[(centroid[0]==-1?0:1)]=x;
    }
    ull calchash(int rt){
        gethash(rt,0);
        return hsh[rt];
    }
}t[2];
inline void solve(){
    cin>>n;
    t[0].buildtree();t[1].buildtree();
    t[0].getcentroid(1,0);t[1].getcentroid(1,0);
    if((t[0].centroid[1]==-1)^(t[1].centroid[1]==-1)){
        puts("NO");
        return;
    }
    if(t[0].calchash(t[0].centroid[0])==t[1].calchash(t[1].centroid[0])){
        puts("YES");
    }
    else if(t[0].centroid[1]!=-1 && t[0].calchash(t[0].centroid[1])==t[1].calchash(t[1].centroid[0])){
        puts("YES");
    }
    else{
        puts("NO");
    }
}
int main(){
    for(int i=2;i<=MAXNUM;i++){
        if(!vis[i]) prime.push_back(i);
        if(prime.size()>=MAXN) break;
        for(auto it:prime){
            if(1LL*it*i>MAXNUM) break;
            vis[it*i]=1;
            if(i%it==0) break;
        }
    }
    // cout<<prime.size()<<' '<<prime.back()<<endl;
    int t;
    cin>>t;
    while(t--){
        solve();
    }
    return 0;
}