cartesian product을 구하는 알고리즘

혹시

이것을 이용하여 구현할 수 있을까요?

c++ 구현 예제입니다; 잘 돌아가는 것 같군요;

#include <string>
#include <vector>
#include <iostream>

using namespace std;

typedef string domain;
typedef vector<domain> tuple;
typedef vector<tuple> table;

table
cp(table t,vector<table> vt)
{
        if(1 == vt.size())
        {
                table result;
                // for each tuple of t
                // original tuple : t[i]
                for(unsigned int i=0;i<t.size();i++)
                {
                        // for each tuple of vt : B
                        for(unsigned int j=0;j<vt[0].size();j++)
                        {
                                tuple temp_tuple(t[i]);
                                // for each column of B
                                for(unsigned int k=0;k<vt[0][j].size();k++)
                                {
                                        // vt[0][j] : table b's jth tuple
                                        temp_tuple.push_back(vt[0][j][k]);
                                }
                                result.push_back(temp_tuple);
                        }
                }
                return result;
        }
        else
        {
                vector<table> one;
                one.push_back(vt[0]);
                vector<table> left;
                for(unsigned int i=1;i<vt.size();i++){left.push_back(vt[i]);}
                return cp(cp(t,one),left);

        }
}

void
print_table(table t)
{
        // for each tuple
        for(unsigned int i=0;i < t.size();i++)
        {
                // for each column
                for(unsigned int j=0;j<t[i].size();j++)
                {
                        cout << "(" << t[i][j] << ") ";
                }
                cout << endl;
        }
}
int
main()
{
        table A;
        tuple a1;
        tuple a2;
        tuple a3;
        a1.push_back("a1");
        a2.push_back("a2");
        A.push_back(a1);
        A.push_back(a2);



        table B;
        tuple b1;
        tuple b2;
        tuple b3;
        b1.push_back("b1");
        b2.push_back("b2");
        b3.push_back("b3");
        B.push_back(b1);
        B.push_back(b2);
        B.push_back(b3);

        table C;
        tuple c1;
        tuple c2;
        tuple c3;
        c1.push_back("c1");
        c3.push_back("c3");
        C.push_back(c1);
        C.push_back(c3);

        vector<table> vt;
        vt.push_back(B);
        vt.push_back(C);

        table result;
        result = cp(A,vt);

        print_table(result);

        return 0;
}