题目描述：
1 #include<iostream> 2 #include<string> 3 #include<set> 4 #include<map> 5 #include<stack> 6 #include<vector> 7 #include<algorithm> 8 using namespace std; 9 10 #define ALL(x) x.begin(),x.end() 11 #define INS(x) inserter(x,x.begin()) 12 13 typedef set<int> Set; 14 map<Set,int> IDcache; // 把集合映射成ID 15 vector<Set> Setcache; // 根据ID取集合 16 17 int ID(Set x){ 18 if(IDcache.count(x)) return IDcache[x] ; 19 Setcache.push_back(x) ; 20 return IDcache[x] = Setcache.size() - 1; 21 } 22 23 int main(){ 24 int t ; 25 cin >> t ; 26 while(t--){ 27 stack<int> s; 28 int n; 29 cin>> n; 30 for(int i=0;i<n;i++){ 31 string op; 32 cin >> op; 33 if(op[0] == 'P') s.push(ID(Set())) ; 34 else if (op[0] == 'D') s.push(s.top()); 35 else{ 36 Set x1 = Setcache[s.top()] ; s.pop(); 37 Set x2 = Setcache[s.top()] ;s.pop() ; 38 Set x ; 39 if (op[0] == 'U') set_union (ALL(x1), ALL(x2), INS(x)); 40 if (op[0] == 'I') set_intersection (ALL(x1), ALL(x2), INS(x)); 41 if (op[0] == 'A') { x = x2; x.insert(ID(x1)); } 42 s.push(ID(x)); 43 } 44 cout << Setcache[s.top()].size() << endl; 45 } 46 cout << "***" << endl; 47 } 48 return 0; 49 }