求 穷举密码 的方法！

Question

密码主要由 123456789abcdefghijklnmopqrstuvwxyz- 组成。我现在设置密码关键字为 qq，生成全部的四位数密码如
0qq0
0qq1
0qq2
0qq3
...
00qq
01qq
02qq
...
aqqa
aqqb
aqqc
..
aaqq
abqq
acqq
...这样穷举下去。请问代码要怎么写？
求高人指点，或共享一下相关案例资源。

Answer 1

            string aaa = "123456789abcdefghijklnmopqrstuvwxyz-";
            String[] Str = new String[(int ) (Math.Pow(aaa.Length, 4))];
            int X = 0;
            char[] bbb = aaa.ToCharArray(0, aaa.Length);
            for (int i = 0; i < bbb.Length; i++)
            {
                for (int j = 0; j < bbb.Length; j++)
                {
                    for (int k = 0; k < bbb.Length; k++)
                    {
                        for (int l = 0; l < bbb.Length; l++)
                        {
                            Str[X] = bbb[i].ToString() + bbb[j].ToString() + bbb[k].ToString() + bbb[l].ToString();
                            X++;
                        }
                    }
                }
            }
我没测试大概这样吧！Str[] 是最后的结果

Answer 2

两个循环就可以 string str = "123456789abcdefghijklnmopqrstuvwxyz-";
            char[] chars = str.ToCharArray();            foreach(char c1 in chars)
            {
                foreach(char c2 in chars)
                {
                    str1 = c1 + "qq" + c2;
                    str2 = c1 + (c2 + "qq");
                    str3 = "qq" + c1 + c2;
                }
            }

Answer 3

 string str = "123456789abcdefghijklnmopqrstuvwxyz-";
            char[] chars = str.ToCharArray();            foreach(char c1 in chars)
            {
                foreach(char c2 in chars)
                {
                    string str1 = c1 + "qq" + c2;
                    string str2 = c1 + (c2 + "qq");
                    string str3 = "qq" + c1 + c2;                    Console.WriteLine(str1);
                    Console.WriteLine(str2);
                    Console.WriteLine(str3);                }
            }