The SetStack Computer UVA - 12096

#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define INF 999999999

typedef set<int> Set;
map<Set,int>Map;
stack<int> st;
vector<Set> v;

int Find(Set s)
{
    if(Map.count(s))
        return Map[s];
    v.push_back(s);
    return Map[s] = v.size()-1;
}

int main()
{
    int T,n;
    cin >> T;
    string s;
    while(T--)
    {
        cin >> n;
        Map.clear();
        v.clear();
        while(!st.empty())
            st.pop();
        for(int i=1;i<=n;i++)
        {
            cin >> s;
            if(s[0] == ‘P‘)
            {
                st.push(Find(Set()));
            }
            else if(s[0]==‘D‘)
            {
                st.push(st.top());
            }
            else
            {
                Set s1 = v[st.top()];
                st.pop();
                Set s2 = v[st.top()];
                st.pop();
                Set temp;
                if(s[0]==‘U‘)
                {
                    set_union(s1.begin(),s1.end(),s2.begin(),s2.end(),inserter(temp,temp.begin()));
                }
                else if(s[0]==‘I‘)
                {
                    set_intersection(s1.begin(),s1.end(),s2.begin(),s2.end(),inserter(temp,temp.begin()));
                }
                else if(s[0]==‘A‘)
                {
                    temp = s2;
                    temp.insert(Find(s1));
                }
                st.push(Find(temp));
            }
            cout << v[st.top()].size() << endl;
        }
        cout << "***" << endl;
    }
    return 0;
}