UVA 12096 The SetStack Computer

<pre name="code" class="cpp">集合中不能有相同元素

set_union，<span style="font-family: Arial, Helvetica, sans-serif;">set_intersection 函数用前就应该保证输入两容器内有序且无重复</span>

<pre name="code" class="cpp">

#include <iostream>
#include <string>
#include <map>
#include <stack>
#include <vector>
#include <set>
#include <algorithm>
#include <cstdio>
#define ALL(x) x.begin(),x.end()
#define INS(x) inserter(x,x.begin())
using namespace std;
typedef set<int> Set;
vector<Set> Setcache;
map<Set,int> IDcache;
int ID(Set x);
int main()
{
int n;
cin>>n;
while(n--)
{
int k;
cin>>k;
stack<int> s;
for(int i=0;i<k;i++)
{
string c;
cin>>c;
if(c[0]=='P') s.push(ID(Set()));  //Set() ：新建一<span style="font-family: Arial, Helvetica, sans-serif;">空集合</span>
else if(c[0]=='D') s.push(s.top());
else
{
Set x1=Setcache[s.top()];s.pop();
Set x2=Setcache[s.top()];s.pop();
Set  x;
if(c[0]=='U') set_union(ALL(x1),ALL(x2),INS(x));
if(c[0]=='I') set_intersection(ALL(x1),ALL(x2),INS(x));
if(c[0]=='A') x=x2,x.insert(ID(x1));
s.push(ID(x));
}
cout<<Setcache[s.top()].size()<<endl;
}
cout<<"***"<<endl;
}
}
int ID(Set x)
{
if(IDcache.count(x)) return IDcache[x];
Setcache.push_back(x);
return IDcache[x]=Setcache.size()-1;
}