JS pascal triangle question

Admin Posts : 140 Join date : 2011-08-01

the following JS code is supposed to output a layer of the pascal triangle :

Code:: function pascal(floor){

var ar1 = [1,1];
if (floor < 2){return '1 1';}

return pascalPt2(floor,2,ar1);
}

function pascalPt2(floor,at,prevfloor)
{
var result = ""; var ar2 = [];ar2[0] = 1;

if (at == floor + 1) {for(var v of prevfloor){result = result + " " + v};return result;}

else{for (var i=0;i<at - 2;i++){ar2[i+1] = prevfloor[i]+prevfloor[i+1]};ar2[at] = 1;}

return pascalPt2(floor,at+1,ar2)

}

console.info(pascal(3))

for the input 3 the output is supposed to be : 1 3 3 1
for the input 4 the output is supposed to be : 1 4 6 4 1
but I get : 1 nan nan 1 and 1 nan nan nan 1 instead
here is the working vb.net code :

Code:: Public Class Form1
   Function pascal(ByVal floor As Integer) As String
   Dim ar1 = New Integer() {1, 1}
   If floor < 2 Then
   Return "1 1"

   End If
   Return pascalPt2(floor, 2, ar1)
   End Function
   Function pascalPt2(ByVal floor As Integer, ByVal at As Integer, ByVal prevfloor As Object) As String
   Dim result = ""
   Dim ar2(at) As Integer
   ar2(0) = 1
   If at = floor + 1 Then
   For Each item As Integer In prevfloor
   result &= item.ToString() & " "

   Next
   Return result
   Else
   For index = 0 To at - 2
   ar2(index + 1) = prevfloor(index) + prevfloor(index + 1)
   Next
   ar2(at) = 1
   End If
   Return pascalPt2(floor, at + 1, ar2)
   End Function
   Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
   MsgBox(pascal(4))
   End Sub
End Class

_________________
kurayami no kagi admin