测试扑克手直抽(4比1)的算法?

#include <iostream>
#include <vector>
#include <hash_map>
#include <numeric>
using namespace std;

const int MAXCARDS = 9;
stdext::hash_map<long long, bool> lookup;

//"Hash function" that is unique for a each set of card ranks, and also
//symmetric so that the order of cards doesn't matter.
long long hash(const vector<int>& cards)
{
    static const int primes[52] = {
        2,3,5,7,11,13,17,19,23,29,31,37,41,
        2,3,5,7,11,13,17,19,23,29,31,37,41,
        2,3,5,7,11,13,17,19,23,29,31,37,41,
        2,3,5,7,11,13,17,19,23,29,31,37,41
    };

    long long res=1;
    for(vector<int>::const_iterator i=cards.begin();i!=cards.end();i++)
        res *= primes[*i];
    return res;
}

//Tests whether there is a straight draw (assuming there is no
//straight). Only used for filling the lookup table.
bool is_draw_slow(const vector<int>& cards)
{
    int ranks[14];
    memset(ranks,0,14*sizeof(int));

    for(vector<int>::const_iterator i=cards.begin();i!=cards.end();i++)
        ranks[ *i % 13 + 1 ] = 1;
    ranks[0]=ranks[13]; //ace counts also as 1

    int count = ranks[0]+ranks[1]+ranks[2]+ranks[3];
    for(int i=0; i<=9; i++) {
        count += ranks[i+4];
        if(count==4)
            return true;
        count -= ranks[i];
    }

    return false;
};

void create_lookup_helper(vector<int>& cards, int idx)
{
    for(;cards[idx]<13;cards[idx]++) {
        if(idx==cards.size()-1)
            lookup[hash(cards)] = is_draw_slow(cards);
        else {
            cards[idx+1] = cards[idx];
            create_lookup_helper(cards,idx+1);
        }
    }
}

void create_lookup()
{
    for(int i=1;i<=MAXCARDS;i++) {
        vector<int> cards(i);
        create_lookup_helper(cards,0);
    }
}

//Test for a draw using the lookup table
bool is_draw(const vector<int>& cards)
{
    return lookup[hash(cards)];
};

int main(int argc, char* argv[])
{
    create_lookup();

    cout<<lookup.size()<<endl; //497419

    int cards1[] = {1,2,3,4};
    int cards2[] = {0,1,2,7,12};
    int cards3[] = {3,16,29,42,4,17,30,43};

    cout << is_draw(vector<int>(cards1,cards1+4)) <<endl; //true
    cout << is_draw(vector<int>(cards2,cards2+5)) <<endl; //true
    cout << is_draw(vector<int>(cards3,cards3+8)) <<endl; //false

}

A 1 J Q

loop through 1 to 13 as i
  if my cards already has this card i, then don't worry about this case, skip to next card
  for this card i, look to the left for number of consecutive cards there is
  same as above, but look to the right
  if count_left_consecutive + count_right_consecutive == 4, then found case

K