Solve Math Problem in MT

[aliasmask]

I was reading this article: http://www.huffingtonpost.com/2015/05/2 ... 46332.html

And I was wondering how I would check each possible permutations. There are a couple of algorithms out there in other languages, but since we're stuck with size 1000 loops how would you do it in MT. A recursive call comes to mind, but I think there is a limit to that as well.

For bonus points, do it in numerical order from low to high, ie 1,2,3,4,5,6,7,8,9 to 9,8,7,6,5,4,3,2,1. BTW, there are 9! combinations for 362880 permutations.

[Akodo Makama]

Recursion can always be traded for memory (especially of you know the maximum recursion depth)

Code: Select all

PrepLists
  [constructedStringList1 = ""]
  [possiblePartsList1 = ""]
  [for(index,1,9): possiblePartsList1 = listAppend(possiblePartsList1, index]
  [PermutateString1()]

PermutateString* (* = 1-8, ^ = *+1)
  [end = listCount(possiblePartsList*) - 1]
  [for (index, 0, end), code:
  {
    [constructedList^ = listAppend(constructedStringList*, listIndex(possiblePartsList*, index))]
    [possiblePartsList^ = listDelete(possiblePartsList*, index]
    [PermutateString^()]
  }

PermutataString9
  [end = listCount(possiblePartsList9) - 1]
  [for (index, 0, end), code:
  {
    [constructedListFinal = listAppend(constructedStringList9, listIndex(possiblePartsList9, index))]
    [checkMathProblem(constructedListFinal)]
  }

 

10 separate functions, (8 of which are functionally identical), each calling the next in the chain. Recursion without recursion.