HDU3791 BST

https://vjudge.net/problem/HDU-3791#

This is the first the time I write the Binary Search Tree by my self

I use the dfs to judge weather the two tree are same

and another methord if the prufer

The code of AC:

#include<bits/stdc++.h>
using namespace std;
int A[100],B[100];
const int inf=1<<30;
struct BST{
    int l,r,val,dat;
}a[100];
int tot=0,root=0,Tot=0;
int New(int val){
    a[++tot].val=val;
    return tot;
}
void Build(){
    memset(a,0,sizeof a);
    tot=0;
    New(-inf),New(inf);
    root=1,a[1].r=2;
}
void Insert(int &p,int val){
    if(p==0){
        p=New(val);
        return;
    }
    if(a[p].val<val) Insert(a[p].l,val);
    else Insert(a[p].r,val);
}
void dfs(int p){
    if(p==0) return;
    A[++Tot]=a[p].val;
    dfs(a[p].l);
    dfs(a[p].r);
    A[++Tot]=a[p].val;
}
void dfs2(int p){
    if(p==0) return;
    B[++Tot]=a[p].val;
    dfs2(a[p].l);
    dfs2(a[p].r);
    B[++Tot]=a[p].val;
}
int main(){
    int n;
    while(cin>>n&&n){
        string s;
        cin>>s;
        Build();
        for(int i=0;i<s.length();++i){
            Insert(root,s[i]-'0');
        }
        memset(A,0,sizeof A);
        Tot=0;
        dfs(root);
        while(n--){
            cin>>s;
            Build();
            for(int i=0;i<s.length();++i){
                Insert(root,s[i]-'0');
            }
            Tot=0;
            memset(B,0,sizeof B);
            dfs2(root);
            int ans=1;
            for(int i=0;i<22;++i){
                if(A[i]!=B[i]){
                    ans=0;
                }
            }
            if(ans) cout<<"YES"<<endl;
            else cout<<"NO"<<endl;
        }
    }
}