Stuck on "All your base"

Programming Java
1

Hello,

i have a problem with the exercise “All your base” in Java. I tested the code on my laptop in BlueJ and on exercism.org. On exercism i get a “tests timed out” message, in BlueJ it works and returns a correct array, atleast for the numbers i tested.

I am quite inexperienced, so any tipps on how to improve the code in general would be appreciated.

import java.util.List;
import java.util.ArrayList;

class BaseConverter {

private final int _originalBase;
private final int[] _originalDigits;

/**
* Constructor of class BaseConverter.
*
* @param originalBase original base of the number
* @param originalDigits original digits of the number
*/
public BaseConverter(int originalBase, int[] originalDigits) 
{
    if (originalBase < 2)
    {
        throw new IllegalArgumentException("Bases must be at least 2.");
    }
    for (int i : originalDigits)
    {
        if (i >= originalBase)
        {
            throw new IllegalArgumentException("All digits must be strictly less than the base.");
        }
        else if (i < 0)
        {
            throw new IllegalArgumentException("Digits may not be negative.");
        }
    }
    
    _originalBase = originalBase;
    _originalDigits = originalDigits.clone();
}

/**
* Converts a number to a different base
*
* @param newBase new base to convert the number to
* @return number in new base
*/
public int[] convertToBase(int newBase) 
{
    int baseTen = convertToTen();

    return helpConvertToNewBase(baseTen, newBase);
}

private int convertToTen()
{
    int tempTen = 0;
    
    for (int i = 0; i < _originalDigits.length; i++)
        {
            tempTen += (int) _originalDigits[i] * Math.pow(_originalBase, _originalDigits.length - i - 1);
        }

    return tempTen;
}

private int[] helpConvertToNewBase(int numberToConvert, int newerBase)
{
    List<Integer> newBaseNumber = new ArrayList<Integer>();

    while (numberToConvert != 0)
        {
            newBaseNumber.add(0 ,numberToConvert % newerBase);
            numberToConvert = numberToConvert / newerBase;
        }
    
    return convertListToArray(newBaseNumber);
}

private int[] convertListToArray(List<Integer> listToConvert)
{
    int[] convertedList = new int[listToConvert.size()];
    for (int i = 0; i < listToConvert.size(); i++)
        {
            convertedList[i] = listToConvert.get(i);
        }

    return convertedList;
}

}

2

Are you running the test suite locally?

3

Thanks for the reply. I did not run the test suite locally, sadly. I could not get that to work properly. I will take this as a nudge to try again :)

I managed to probably fix the error though through your question. I looked again at the test cases and noticed i only check for a base minimum in the constructor, not the method that changes the bases.

So now it clears the tests. Thank you!

4

You could check if List has a method to convert to an array… List (Java SE 11 & JDK 11 )

5

Ah, thats nice. I have no idea why i didn’t use that. Somehow i thought there was only Array.asList not the other way around…

Thanks alot!