Android Question Short code for generating word list combination?

stevel05 said:

Maybe something like this:

B4X:

    Dim NumMap As B4XOrderedMap
    NumMap.Initialize
 
 
    Dim I,J,K As Int
    Dim SB As StringBuilder
    For I = 97 To 122
        For J = 97 To 122
            For K = 97 To 122
                SB.Initialize
                SB.Append(Chr(I))
                SB.Append(Chr(J))
                SB.Append(Chr(K))
                NumMap.Put(SB.ToString,1)
            Next
        Next
    Next
 
    Log(NumMap.Keys.Size)
    Log(26*26*26)

A normal Map is about 25% quicker (14ms vs 19 ms on my machine), but this is cross platform, and you can sort the result if needed.

Click to expand...

stevel05 said:

Even quicker if you just use a list. I used a map as i initially though there may be duplicates, but ended up not being any.

B4X:

    Dim StartTime As Long = DateTime.Now
    Dim L As List
    L.Initialize

    Dim I,J,K As Int


    For i = 97 To 122
        For J = 97 To 122
            For K = 97 To 122
                L.Add(Chr(I) & Chr(J) & Chr(K))
            Next
        Next
    Next

    Log("Complete in " & (DateTime.Now - StartTime) & " ms")
    Log(L.Size)
    Log(26*26*26)

Click to expand...

Sub Combine
    Dim StartTime As Long = DateTime.Now
    Dim L As List
    L.Initialize

    Combine(L,"",3)
    Log("Complete in " & (DateTime.Now - StartTime) & " ms")
    Log(L.Size)
    Log(26*26*26)
End Sub

Private Sub Combine(ListComb As List, Prefix As String, Level As Int)
    If Level>0 Then
        For i = 97 To 122
            Combine(ListComb,Prefix & Chr(i), Level-1)
        Next
    Else
        ListComb.Add(Prefix)
    End If
End Sub