BZOJ1932 [Shoi2007]Setstack 集合堆栈机

妈呀。。。clj大爷太强啦！

原来还有set_union和set_intersection这种东西。。。

于是只要把栈顶的每个元素hash一下记录到一个vector里去就好了

 /**************************************************************
     Problem: 1932
     User: rausen
     Language: C++
     Result: Accepted
     Time:148 ms
     Memory:3372 kb
 ****************************************************************/

 #include <cstdio>
 #include <vector>
 #include <stack>
 #include <algorithm>

 using namespace std;
 typedef unsigned long long ull;
 typedef vector <ull> vec;
 const int N = 2e3 + ;
 const int base = ;

 inline ull add(const vec &v) {
     static ull res;
     static int i;
     for (i = res = ; i < v.size(); ++i)
         res *= base, res += v[i] + ;
     return res;
 }

 inline void get(vec &v) {
     sort(v.begin(), v.end());
     v.resize(unique(v.begin(), v.end()) - v.begin());
 }

 int n, top;
 vec S[N];

 int main() {
     int i;
     char st[];
     vec a, b, c(N);
     scanf("%d",&n);
     for (i = ; i <= n; ++i) {
         scanf("%s", st + );
         if (st[] == 'P') {
             S[++top] = vec();
             goto end;
         }
         if (st[] == 'D') {
             ++top, S[top] = S[top - ];
             goto end;
         }
         a = S[top--], b = S[top--];
         if (st[] == 'A') {
             b.push_back(add(a)), get(b);
             S[++top] = b;
             goto end;
         }
         c = vec(a.size() + b.size());
         if (st[] == 'U') {
             c.resize(set_union(a.begin(), a.end(), b.begin(), b.end(), c.begin()) - c.begin());
             get(c), S[++top] = c;
             goto end;
         }
         if (st[] == 'I') {
             c.resize(set_intersection(a.begin(), a.end(), b.begin(), b.end(), c.begin()) - c.begin());
             get(c), S[++top] = c;
             goto end;
         }
         end : printf("%d\n", S[top].size());
     }
     return ;
 }