Fix "C-style for statement is deprecated" in Swift

I have been trying to fix this error is about 5 different sections of my code. How can I remove this waing. Thanks!!

        for var i=0; i<gameState.count && bestMove == -1; i += 1
    {
        if gameState[i] == 0 {
            gameState[i] = 2
            checkWierMove()
            if isWier == true{
                bestMove = i
                isWier = false
                gameState[i] = 0
                buttonPressed(self.view.viewWithTag(i+1)!)
            }else{
                gameState[i] = 0
            }
        }

    }