ShufflingCardsDiv2.cpp

class ShufflingCardsDiv2 {
    public:
    string shuffle(vector<int> permutation) {

      const int n=permutation.size();
      vector<int> ga,gb;
      for(int i=0;i<n;i++)
        {
          if(i%2==0)
            ga.push_back(permutation[i]);
          else
            gb.push_back(permutation[i]);
        }
      sort(ga.begin(),ga.end());
      sort(gb.begin(),gb.end());

      vector<int> a,b;
      int ac=0;
      int bc=0;
      for(int i=1;i<=n;i++)
        {
          if(i<=n/2)
            a.push_back(i);
          else
            b.push_back(i);
        }
      for(int i=0;i<ga.size();i++)
        {
	  if(find(a.begin(),a.end() ,ga[i])!=a.end())
	    ac++;
	  if(find(b.begin(),b.end() ,ga[i])!=b.end())
	    bc++;
	}
      if(ac==(n/4)+(n/2)%2)
        return "Possible";
      else
	return "Impossible";
    }
};