数字合
求2的3位合, 如入0,1, 需出:
000
001
010
011
111
110
100
101

[解决办法]
http://www.cnblogs.com/rogerwei/archive/2010/11/18/1880336.html
[解决办法]

            int[] ary = { 0, 1 };
            var source = from t1 in ary from t2 in ary from t3 in ary select new { s = "" + t1 + t2 + t3 };
            foreach (var t in source)
                Console.WriteLine(t.s);