UVa 12096 (STL) the Setstack computer

Test instructions

There is a collection stack computer, the elements in the stack are all collections, and there are some related operations. Outputs the number of stack elements at the top of each operation.

Analysis:

The problem feels a bit abstract, set can also set set, but the problem with the set of the figure is very appropriate.

By mapping the set to an ID, you can use stack<int> to simulate the stack of stacks in a problem, and then use Vector<set> to index the collection based on the subscript.

The code is short, but it needs to be understood more.

1#include <cstdio>2#include <string>3#include <vector>4#include <stack>5#include <Set>6#include <map>7#include <iostream>8#include <algorithm>9 using namespacestd;Ten  OnetypedefSet<int>Set; AMap<set,int>Idcache; -Vector<set>Setcache; -  the #defineAll (x) X.begin (), X.end () - #defineINS (x) Inserter (X,x.begin ()) -  - intID (Set x) + { -     if(Idcache.count (x))returnIdcache[x]; + setcache.push_back (x); A     returnIDCACHE[X] = setcache.size ()-1; at } -  - intMain () - { -     //freopen ("In.txt", "R", stdin); -  in     intT; -scanf"%d", &T); to      while(t--) +     { -stack<int>s; the         intN; *scanf"%d", &n); $          for(inti =0; I < n; ++i)Panax Notoginseng         { -             stringop; theCIN >>op; +             if(op[0] =='P') S.push (ID (Set () )); A             Else if(op[0] =='D') S.push (S.top ()); the             Else +             { -Set x1 =setcache[s.top ()]; S.pop (); $Set x2 =setcache[s.top ()]; S.pop (); $ Set x; -                 if(op[0] =='U') set_union (All (x1), All (x2), INS (x)); -                 if(op[0] =='I') set_intersection (All (x1), All (x2), INS (x)); the                 if(op[0] =='A') {x =x2; X.insert (ID (x1));} - S.push (ID (x));Wuyi             } theprintf"%d\n", Setcache[s.top ()].size ()); -         } Wu  -Puts"***"); About     } $  -     return 0; -}

code June

UVa 12096 (STL) the Setstack computer