KattisAnimalsSlow

#include <iostream>
#include <list>
#include <algorithm>
#include <string>
#include <unordered_set>
#include <deque>

using namespace std;


struct hash_X{
  size_t operator()(const unordered_set<int> &x) const{
    int sum = 0;
    for(int i: x){sum = sum+i;}
    return sum;
  }
};

unordered_set<unordered_set<int>, hash_X> mt(list<string> L){
    unordered_set<unordered_set<int>, hash_X> S;
    list<string> K;
    deque<list<string>> Q;
    Q.push_back(L);
    while(Q.size() > 0){
        K = Q.back();
        unordered_set<int> tmp;
        for(string s: K){if( s!="(" and s!=")" ){int i = stoi(s); tmp.insert(i);}}
        S.insert(tmp);
    //K is of the form for example (x(yz)), so first we unwrap ~ x(yz) and split into the two subtrees x and (yz)
    //and add both to the queue. If only one node is left ( x ) we dont add it back to the queue
        if(K.size() >= 2){
            K.pop_front();
            K.pop_back();
            list<string>::iterator it = K.begin();
            if(*it == "("){
                int i = 1;
                while(i != 0){
                    it++;
                    if(*it == ")"){i = i-1;}
                    else if(*it == "("){i=i+1;}
                    }
                }
            it++;
            list<string> B;
            list<string>::iterator itB = B.begin();
            B.splice(itB, K, it, K.end());
            Q.push_front(K);
            Q.push_front(B);
        }
        Q.pop_back();
    }
    return S;
}


int main(){
    int n;
    string x, y;
    char c;
    list<string> A, B;
    cin >> n;
    cin.ignore();
    cin >> x;
    cin >> y;
    // parse ((3,(1,(5,2))),4) into ((3(1(52)))4)
    for(int i = 0; i < x.size(); i++){
        string c = "";
        c += x[i];
        if( c == "(" or c == ")" ){A.push_back(c);}
        if( isdigit(x[i]) ){
            string tmp = "";
            while( isdigit(x[i]) ){
                tmp += x[i];
                i++;
            }
            i--;
            A.push_back(tmp);
        }
    }
    for(int i = 0; i <= y.size(); i++){
        string c = "";
        c += y[i];
        if( c == "(" or c == ")" ){B.push_back(c);}
        if( isdigit(y[i]) ){
            string tmp = "";
            while( isdigit(y[i]) ){
                tmp += y[i];
                i++;
            }
            i--;
            B.push_back(tmp);
        }
    }

    // make the trees
    unordered_set<unordered_set<int>, hash_X> t1 = mt(A);
    unordered_set<unordered_set<int>, hash_X> t2 = mt(B);
    unordered_set<unordered_set<int>, hash_X> i(t1.begin(), t1.end());
    int res = count_if(t2.begin(), t2.end(), [&](unordered_set<int> k) {return i.find(k) != i.end();});
    cout << res;
}