Question

To the HighArray class in the highArray.java, add a method called getMax() that returns the value of the highest key in the array, or -1 if the array is empty. Add some code in main()
to exercise this method. You can assume all the keys are positive numbers.

// highArray.java
class HighArray
{
private long[] a;
private int nElems;   
public HighArray(int max)   
{
a = new long[max];   
nElems = 0;
}
public boolean find(long searchKey)
{
int j;
for(j=0; j<nElems; j++)   
if(a[j] == searchKey)   
break;   
if(j == nElems)
return false;   
else
return true;
}
public void insert(long value)
{
a[nElems] = value;   
nElems++;
}
public boolean delete(long value)
{
int j;
for(j=0; j<nElems; j++)
if( value == a[j] )
break;
if(j==nElems)
return false;
else   
{
for(int k=j; k<nElems; k++)
a[k] = a[k+1];
nElems--;   
return true;
}
}
public void display()   
{
for(int j=0; j<nElems; j++)   
System.out.print(a[j] + " ");
System.out.println("");
}

}
class HighArrayApp
{
public static void main(String[] args)
{
int maxSize = 100;
HighArray arr;
arr = new HighArray(maxSize);

arr.insert(77);   
arr.insert(99);
arr.insert(44);
arr.insert(55);
arr.insert(22);
arr.insert(88);
arr.insert(11);
arr.insert(00);
arr.insert(66);
arr.insert(33);

arr.display();

int searchKey = 35;   
if( arr.find(searchKey) )
System.out.println("Found " + searchKey);
else
System.out.println("Can't find " + searchKey);

arr.delete(00);   
arr.delete(55);
arr.delete(99);

arr.display();
}
}

Answer 1

// highArray.java
class HighArray {
    private long[] a;
    private int nElems;

    public HighArray(int max) {
        a = new long[max];
        nElems = 0;
    }

    public boolean find(long searchKey) {
        int j;
        for (j = 0; j < nElems; j++)
            if (a[j] == searchKey)
                break;
        if (j == nElems)
            return false;
        else
            return true;
    }

    public void insert(long value) {
        a[nElems] = value;
        nElems++;
    }

    public boolean delete(long value) {
        int j;
        for (j = 0; j < nElems; j++)
            if (value == a[j])
                break;
        if (j == nElems)
            return false;
        else {
            for (int k = j; k < nElems; k++)
                a[k] = a[k + 1];
            nElems--;
            return true;
        }
    }

    public void display() {
        for (int j = 0; j < nElems; j++)
            System.out.print(a[j] + " ");
        System.out.println("");
    }

    public long getMax() {
        if (nElems == 0) {
            return -1;
        } else {
            long max = a[0];
            for (int i = 0; i < nElems; i++) {
                if (a[i] > max) {
                    max = a[i];
                }
            }
            return max;
        }
    }
}

class HighArrayApp {
    public static void main(String[] args) {
        int maxSize = 100;
        HighArray arr;
        arr = new HighArray(maxSize);

        arr.insert(77);
        arr.insert(99);
        arr.insert(44);
        arr.insert(55);
        arr.insert(22);
        arr.insert(88);
        arr.insert(11);
        arr.insert(00);
        arr.insert(66);
        arr.insert(33);

        arr.display();

        int searchKey = 35;
        if (arr.find(searchKey))
            System.out.println("Found " + searchKey);
        else
            System.out.println("Can't find " + searchKey);

        arr.delete(00);
        arr.delete(55);
        arr.delete(99);

        arr.display();

        System.out.println("Maximum number in array is " + arr.getMax());
    }
}