Question

I am having trouble adding an item to my array set, it should be ordered in ascending order and for some reason I just get to add it and it does not order it.

Here is my code:

public boolean add(AnyType x){
    if(this.contains(x))
        return false;
    else if(this.isEmpty()){
        items[theSize]=x;
        theSize++;
        return true;
    }
    else{
    if( theSize == items.length )
        this.grow();
    //Here goes code for adding
    /*AnyType[] newItems = (AnyType[]) new Comparable[items.length];
    newItems = items;
    for(int i=0;i<theSize;i++)
        if(items[i].compareTo(x)>0){
            newItems[i]=x;
            newItems[i+1]=items[i];
            for(int j=i+1;j<theSize;j++)
                newItems[j]=items[i];
            items = newItems;
            theSize++;
            return true;
        }

    //*/
    items[theSize]=x; //*/
    theSize++;
    return true;
    }
}

The method should not allow an item to repeat so if you try to add something that is already in there, it should return false. If the array is empty just add to items[0] and then I tried to create a new array and once you find an item bigger than the one I’m inputing copy everything into a new array, add the new value, and just add the rest and then make items = newItems; but it did not work. I have been trying for a couple hours now so I just decided to ask for help.
I have my SortedSet class defined like this:

public class SortedSet<AnyType extends Comparable> implements Set<AnyType>
{
    private AnyType[] items;
    private int theSize;
    public SortedSet(){
        theSize = 0;
        items = (AnyType[]) new Comparable[5];
    }

I know there are other ways to do this like using TreeMap but it has to be done as an array.

Thanks

Answer 1

I do not see where you are writing the previous values?

Try something like this in the last else.

            theSize++;
            AnyType[] newItems = new AnyType[theSize];
            for(int i = 0; i < theSize-1; i++)
                if(items[i].compareTo(x) > 0)
                {
                    newItems[i] = x;
                    newItems[i + 1] = items[i];
                    for(int j = i + 2; j < theSize; j++)
                        newItems[j] = items[j-1];
                    items = newItems;
                    return true;
                }
                else
                    newItems[i] = items[i];
            newItems[theSize-1] = x;
            items = newItems;
            return true;

Since I already coded it to make sure it works fine, here is a sample working on Strings. I focused here only on correct adding. The other issues important for the OP were omitted.

import java.util.Arrays;

public class OrderingAddTest
{
    static int theSize = 0;
    static String[] items = new String[theSize];
    public static void main(String[] args)
    {
        add("a");
        add("e");
        add("d");
        add("b");
        add("c");

        System.out.println(Arrays.toString(items)+"\n; items.length="+items.length);
    }

    private static boolean add(String x)
    {
        theSize++;
        String[] newItems = new String[theSize];
        for(int i = 0; i < theSize - 1; i++)
            if(items[i].compareTo(x) > 0)
            {
                newItems[i] = x;
                newItems[i + 1] = items[i];
                for(int j = i + 2; j < theSize; j++)
                    newItems[j] = items[j - 1];
                items = newItems;
                return true;
            }
            else
                newItems[i] = items[i];
        newItems[theSize - 1] = x;
        items = newItems;
        return true;
    }
}