用算法如何实现类似数据库中的笛卡尔积？
有n类事件，每一类事件又有若干个例子。如A（1，2，3），B（1，2，3），C（1，2），D（1，2），现在要对各个事件的例子组合进行操作，请问如何对这些组合进行存储，也就是采用何种数据结构比较合理？我用例子说明组合的意思：每个事件单独表示为下面的表：
table1 table2 table3 table4
A B C D
------- ------- ------ -----
1 1 1 1
2 2 2 2
3 3
当事件之间两两组合时，就得到以下六个表:
table5 table6 table7 table8 table9 table10
AB AC AD B C BD C D
------- ------- ----- ------- ------ -------
11 11 11 11 1 1 1 1
12 12 12 12 1 2 1 2
13 21 21 21 2 1 2 1
21 22 22 22 2 2 2 2
22 31 31 31 3 1
23 32 32 32 3 2
31
32
33
当事件每三个三个组合时，得到下面的表：
table11 table12 table13 table14
ABC ABD ACD BCD
--------- -------- -------- --------
111 111 111 111
112 112 112 112
121 121 121 121
122 122 122 122
131 131 211 211
132 132 212 212
. . . .
. . . .
. . . .
. . . .
四个事件之间组合得到下面的表：
table15
A B C D
------------------
1 1 1 1
1 1 1 2
1 1 2 1
1 1 2 2
1 2 1 1
1 2 1 2
.
.
.
.
我要如何对这些表进行统一的表示呢？也就是采用何种数据结构比较合理？ 已解决，在csdn 上找到了正解，跟大家分享一下！
以4类事件为例：
string[][] a = new string[];
a = new string[] { "king", "of", "the", "world" };
a = new string[] { "cs", "app" };
a = new string[] { "good", "cool", "dev" };
a = new string[] { "king", "of", "the"};
System.Collections.ArrayList arrlist = new System.Collections.ArrayList();
int[] index = new int;
while (index < a.Length)
{
string temp = "";
for (int i = 0; i < index.Length; i++)
{
temp += a] + "&";
}
arrlist.Add(temp.Substring(0, temp.Length - 1));
index++;
for (int i = index.Length - 1; i > 0; i--)
{
if (index >= a.Length)
{
index = 0;
index++;
}
}
}
Array b = arrlist.ToArray(typeof(string)); 测试结果
king&cs&good&king
king&cs&good&of
king&cs&good&the
king&cs&cool&king
king&cs&cool&of
king&cs&cool&the
king&cs&dev&king
king&cs&dev&of
king&cs&dev&the
king&app&good&kin
king&app&good&of
king&app&good&the
king&app&cool&kin
king&app&cool&of
king&app&cool&the
king&app&dev&king
king&app&dev&of
king&app&dev&the
of&cs&good&king
of&cs&good&of
of&cs&good&the
of&cs&cool&king
of&cs&cool&of
of&cs&cool&the
of&cs&dev&king
of&cs&dev&of
of&cs&dev&the
of&app&good&king
of&app&good&of
of&app&good&the
of&app&cool&king
of&app&cool&of
of&app&cool&the
of&app&dev&king
of&app&dev&of
of&app&dev&the
the&cs&good&king
the&cs&good&of
the&cs&good&the
the&cs&cool&king
the&cs&cool&of
the&cs&cool&the
the&cs&dev&king
the&cs&dev&of
the&cs&dev&the
the&app&good&king
the&app&good&of
the&app&good&the
the&app&cool&king
the&app&cool&of
the&app&cool&the
the&app&dev&king
the&app&dev&of
the&app&dev&the
world&cs&good&kin
world&cs&good&of
world&cs&good&the
world&cs&cool&kin
world&cs&cool&of
world&cs&cool&the
world&cs&dev&king
world&cs&dev&of
world&cs&dev&the
world&app&good&ki
world&app&good&of
world&app&good&th
world&app&cool&ki
world&app&cool&of
world&app&cool&th
world&app&dev&kin
world&app&dev&of
world&app&dev&the
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