Question

I’ll try to explain it better.

So k = 2.
In[]profits = new {1, 2, 3, 1, 6, 10}

For the first part it should be:

1,2,3

Then look for the least value in {1,2,3} which is 1. Then add that to the next value which is 1. So it would be 1+1. The outcome would be {2,3,2}. Again look for the least value which is 2 and add it to the next value 6. So it would be 2+6. The outcome would be {3, 2, 8}. Finally, for the least value in {3,2,8} and add it to the next value 10. So it would be and 10+2. The outcome is {2, 8, 10}. Then look for the least value in that which is 2.

If you guys could at least guide me on how to do this?

This is the tester:

import java.util.Arrays ;

 /**
 Presents some problems to the BillBoard class.
 */

public class BillboardTester {

    public static void main(String[] args) {
    int[] profits = new int[]{1, 2, 3, 1, 6, 10} ;

        int k = 2 ;

        System.out.println("Profits: " + Arrays.toString(profits) + "   k = " + k)  ;

        Billboard bb = new Billboard(profits, k) ;
        System.out.println("Maximum Profit = " + bb.maximumProfit()) ;
        System.out.println(bb) ;

        k = 3 ;
        profits = new int[]{7, 4, 5, 6, 1, 7, 8, 9, 2, 5} ;
        System.out.println("Profits: " + Arrays.toString(profits) + "   k = " + k)  ;
        bb = new Billboard(profits, k) ;
        System.out.println("Maximum Profit = " + bb.maximumProfit()) ;
        System.out.println(bb) ;
    }
}

This is what I have so far for the class:

public class Billboard {
    private int maximumprofit; // The max profit 
    private int finalcost; // The final cost of removing the billboards

    public Billboard(int[]profits, int k) {
        for (int i = 0; i < profits.length; i++) {
            maximumprofit+= profits[i];
        }
    }

    public int maximumProfit() {
        return maximumprofit;
    }
}

Answer 1

If I understand your problem correctly, you have k+1 possible totals, and you add each new element of profits to the LOWEST current total profit no matter what it is. So in your example, it’s really

• 1, 2, 3
• 1+1=2, 2, 3
• 2+6=8, 2, 3
• 8, 2+10=12, 3

For a final array of

• 8, 12, 3 -> Lowest value is actually 3

If this is what you meant (you never said what k is), this code will do the job. I left a line of debugging code in there to help you check for correctness.

public class Billboard
{
    private int[] profits;
    private int k;
    public Billboard(int[]profits, int k)
    {
        this.profits = profits;
        this.k = k+1; // I changed this to k+1 because you have 3 totals with k = 2
    }
    public int maximumProfit() {
        int[] bottom = new int[k];

        for(int i = 0; i < profits.length; i++) {
            int minIndex = 0;
            int min = Integer.MAX_VALUE;
            for (int j = 0; j < k; j++) {
                if (bottom[j] < min) {
                    minIndex = j;
                    min = bottom[j];
                }
            }
            bottom[minIndex] += profits[i];
        }

        int min = Integer.MAX_VALUE;
        for(int i = 0; i < k; i++) {
            System.out.println("TestDump: #"+i+" is: " + bottom[i]);
            if (bottom[i] < min) {
                min = bottom[i];
            }
        }

        return min;
    }

    public static void main(String args[]) {
        Billboard bb = new Billboard(new int[]{1,2,3,1,6,10}, 2);
        System.out.println("Maximum profit = " + bb.maximumProfit());
    }
}

This code outputs

TestDump: #0 is: 8
TestDump: #1 is: 12
TestDump: #2 is: 3
Maximum profit = 3

To change what the Billboard class outputs when you put it in System.out.println(bb), you have to override the toString method of the Billboard class, i.e.

@Override
public String toString() {
    return (new StringBuider(totalProfit - maxProfit)).toString();
}

Assuming you set the fields in the class to have the correct values earlier.