Disabling all UITableView cells except the last one - Swift - ios

Question

Currently working with UITableView in swift.
Since my table cell values are appending by clicking the button i want to figure out a way to disable interaction for all the previous cells, except the last one.
I've played with array-based approach a little, but it didn't work out the way i wanted.
var disabledRows = [0,1,2]
else
{
cell.backgroundColor = UIColor.orangeColor()
}
if (contains(disabledRows, indexPath.row)) {
cell.userInteractionEnabled = false
}
else {
cell.userInteractionEnabled = true
}
The issue with this approach is that i have to count all cells and then block the last one.
Maybe there are some easier approaches?
Any help much appreciated.
Update - here is my complete "cellForRowAtIndexPath" function
func tableView(tableView: UITableView, cellForRowAtIndexPath
indexPath: NSIndexPath) -> UITableViewCell
{
let cell: CustomCellForTableViewTableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! CustomCellForTableViewTableViewCell
if indexPath.row % 2 == 0
{
cell.backgroundColor = UIColor.purpleColor()
}
else
{
cell.backgroundColor = UIColor.orangeColor()
}
if (contains(disabledRows, indexPath.row)) {
cell.userInteractionEnabled = false
}
else {
cell.userInteractionEnabled = true
}
let quest = arrayOfQuestions[indexPath.row]
cell.setCell(type.Grocery, optionno1:type.option1, optionno2:type.option2)
cell.mainText.text = type.Grocery
cell.optionOne.backgroundColor = UIColor.redColor()
return cell
}

Answer 1

In cellForRowAtIndexPath: method.
if (indexPath.row == yourDataSourceArray.count - 1) {
// enable cell
} else {
// disable cell
}