100722B

在stack里套set，然后每次根据他的操作，在set里操作，把括号hash，插入，输出set的size-1

#include<iostream>
#include<set>
#include<cstdio>
#include<stack>
#define ll long long
#define st set<ll>
using namespace std;
stack<st>s;
ll T,n,tot;
char S[];
int main()
{
    cin>>T;
    while(T--)
    {
        cin>>n;
        while(!s.empty())s.pop();
        for(int i=;i<=n;i++)
        {
            scanf("%s",S);
            if(S[]=='P')
            {
                st x;x.clear();
                x.insert();
                s.push(x);
                printf("%d\n",);
            }
            if(S[]=='D')
            {
                st a;a.clear();
                a=s.top();
                ll temp=a.size()-;
                s.push(a);
                printf("%d\n",temp);
            }
            if(S[]=='U')
            {
                st a=s.top();s.pop();
                st b=s.top();s.pop();
                for(st::iterator it=a.begin();it!=a.end();it++)
                    b.insert(*it);
                s.push(b);
                printf("%d\n",b.size()-);
            }
            if(S[]=='I')
            {
                st a=s.top();s.pop();
                st b=s.top();s.pop();
                st c;c.clear();
                for(st::iterator it=a.begin();it!=a.end();it++)
                    if(b.count(*it))c.insert(*it);
                s.push(c);
                printf("%d\n",c.size()-);
            }
            if(S[]=='A')
            {
                st a=s.top();s.pop();
                st b=s.top();s.pop();
                st c;c.clear();
                ll sum=;
                for(st::iterator it=a.begin();it!=a.end();it++)
                    {sum*=;sum+=*it;}
                sum*=;
                b.insert(sum);
                s.push(b);
                printf("%d\n",b.size()-);
            }
        }
        printf("***\n");
    }
    return ;
}