Fixed Place Permutation/Combination

Question

I am looking for a way where I can generated different combination of 4 sets elements in such a manner that every set's element has a fixed place in the final combination: To explain better my requirement let me give sample of those 4 sets and finally what I am looking for:

Set#1(Street Pre Direction) { N, S } Set#2(Street Name) {Frankford, Baily} Set#3(Street Type) {Ave, St} Set#4(Street Post Direction) {S}

Let me list few expecting combinations:
N Baily Ave S
S Frankford St S
S Baily Av S
.
.
.

Now as you can see that every set's element is falling into its place
Pre Direction is in Place 1
Street Name is in Place 2
Streety Type is in Place 3
Street Description is in Place 4

I am looking for the most efficient way to carry out this task, One way to do it is to work at 2 sets at a time like:
Make Combination of Set 1 and Set 2 --> create a new set 5 of resulting combinations
Make Combination of Set 5 and Set 3 --> create a new set 6 of resulting combinations
Make Combination of Set 6 and Set 4 --> This will give me the final combinations

Is there a best way to do this thing? Kindly help. I will prefer C# or Java.

Thanks

Answer 1

It sounds like you're looking for the cartesian product of some sets. You can do it using nested for loops. Here's the Haskell code, which you didn't ask for.

Prelude> [[x,y] | x <- ['1'..'3'], y <- ['A'..'C']]
["1A","1B","1C","2A","2B","2C","3A","3B","3C"]

Answer 2

Here's some linq (c#) that gives you all combinations, it is not "the most efficient way".

var query =
  from d in predirections
  from n in names
  from t in types
  from s in postdirections
  select new {d, n, t, s};

Answer 3

@ David B What if predirections list is empty, is there a way that we still get the combinations since through your way none cartesian product will be returned.

---

David B here:

var query =
  from d in predirections.DefaultIfEmpty()
  from n in names.DefaultIfEmpty()
  from t in types.DefaultIfEmpty()
  from s in postdirections.DefaultIfEmpty()
  select new {d, n, t, s};