Need help with max/min'ing multiply
 

I've been given a project in which I have to find the highest and lowest possible product using 3 2-digit numbers without repeating any numbers.

For example, the algorithm for the highest would be:
7n * 8n * 9n where the n's would be 4, 5, or 6.
The algorithm for the lowest would be:
1n * 2n * 3n where the n's would be 4, 5, or 6.

So far, I know I will have to give an option of finding the lowest or highest, so I would ask the user to put in 0 to minimize and 1 to maximize. Now, I have thought of using an if statement for reading their input, but I need some kind of loop that will rearrange the 4's, 5's, or 6's. I thought of attaching the values of 4, 5, and 6 to the 90, 80, 70, or 10, 20, 30, but am unsure of how I would code a proper loop or simple if statement to find the best answer by trying each combination. In theory, I could make some really over-extensive amount of code to do it right, but it wouldn't follow curriculum.

The code I have so far is

public class Powers

{ 

    public static void main(String[] args);

    

        int input;

        int numOneTensLow = 10;

        int numTwoTensLow = 20;

        int numThreeTensLow = 30;

        int numOneOnesLow = 4;

        int numTwoOnesLow = 5;

        int numThreeOnesLow = 6;

        int numOneTensHigh = 90;

        int numTwoTensHigh = 80;

        int numThreeTensHigh = 70;

        int numOneOnesHigh = 6;

        int numTwoOnesHigh = 5;

        int numThreeOnesHigh = 4;

        int numOneLow;

        int numTwoLow;

        int numThreeLow;

        int numOneHigh;

        int numTwoHigh;

        int numThreeHigh;

        int lowproduct = (numOneLow * numTwoLow * numThreeLow);

        int highprodcut = (numOneHigh * numTwoHigh * numThreeHigh);

        

        ConsoleIO console = new ConsoleIO();

        System.out.println("This program will calculate three two-digit" +

        " numbers that create the lowest and highest possible products " +

        "using the numbers 1 through 9 once in each.");

        System.out.println("To calculate the highest input 1, to calculate" +

        " the lowest, input 0: ");

        input = console.readInt();

        

        if(int input = 0);

        {

            do

            {

                numOneTensLow + NumOneOnesLow;

                numTwoTensLow + NumTwoOnesLow;

                numThreeTensLow + NumThreeOnesLow;

                System.out.println((numOneTensLow + numOneOnesLow) * (NumTwoTensLow + NumTwoOnesLow)

                * (NumThreeTensLow + NumThreeOnesLow));

                }

            }

Re: Need help with max/min'ing multiply
 

Base condition - use any java editor or IDE (NetBeans,Eclipse,BlueJ....)
What is this ?

public static void main(String[] args);

Post formally proper code.

quuba

Re: Need help with max/min'ing multiply
 

I could help you with a little bit of help from your side first.Pls detail your problem and also comment your code wherever appropriate.

Re: Need help with max/min'ing multiply
 

would love to help you imbestatjava, but i have no clue what you are trying to do

multiply by numbers by products of 7,8,9 and 1,2,3?
that part is understandable, but what is this?
i don't get what these values have to do with anything

Re: Need help with max/min'ing multiply
 

The values 90, 80, 70 and 10, 20, 30 have a lot to do with the program because im trying to find the highest possible combination of 9n, 8n, and 7n so it'd be (90 + n) * (80 + n) * (70 + n) where every n must be either 4, 5, or 6. So far the only error I can actually see is in the line of code

public static void main(String[] args);

Re: Need help with max/min'ing multiply
 

I think you need to do something like this :

highProduct1 = (numOneTensHigh + numOneOnesHigh) * 

                                        (numTwoTensHigh + numTwoOnesHigh) * 

                                         (numThreeTensHigh + numThreeOnesHigh);

        

        highProduct2 = (numOneTensHigh + numTwoOnesHigh) * 

                                    (numTwoTensHigh + numOneOnesHigh) * 

                                         (numThreeTensHigh + numThreeOnesHigh);

        

        highProduct3 = (numOneTensHigh + numThreeOnesHigh) * 

                                        (numTwoTensHigh + numTwoOnesHigh) * 

                                         (numThreeTensHigh + numOneOnesHigh);



        highProduct4 = (numOneTensHigh + numOneOnesHigh) * 

                                    (numTwoTensHigh + numThreeOnesHigh) * 

                                     (numThreeTensHigh + numTwoOnesHigh);

        

        // This way try all combinations, if there are left any others ;-)

        // then get the max of them.

        

        if (max < highProduct1)

                max = highProduct1;

        

        if (max < highProduct2)

                max = highProduct2;

        

        if (max < highProduct3)

                max = highProduct3;

        

        if (max < highProduct4)

                max = highProduct4;

        

        // In the end print out the highest product

        System.out.println("Highest product is : " + max);

You can do the same way for the Lowest product.

Re: Need help with max/min'ing multiply
 

read again #2
quuba

Re: Need help with max/min'ing multiply
 

Your theme posted here is interesting. Min/max, combinatoric algorithms.
Line

public static void main(String[] args);

change to

public static void main(String[] args){

Add

}}

at end of program.
Download from http://www.netbeans.org/ NetBans IDE 6.5, select Java SE 37 MB.
and Java SE Development Kit (JDK) 6 Update 11 from http://java.sun.com/javase/downloads/index.jsp ,

or

JDK 6 Update 11 with NetBeans 6.5 from http://java.sun.com/javase/downloads/index.jsp .
It's free.
Install and work.
Advanced editor show to You all wrong points in code before compiling.

Re: Need help with max/min'ing multiply
 

I'm supposed to use BlueJ and its supposed to be a three-way multiplication, so I was hoping there could be some kind of loop I could use for this. An example for the maximization would be:
(90 + 6) * (80 + 5) * (70 +4)
And minimization would look like:
(10 + 5) * (20 + 6) * (30 + 4)
And somehow in a loop I would have to try each combination, so if I were to do each individually it would look like a bunch of lines of this:
14 * 25 * 36
14 * 26 * 35
15 * 26 * 34
15 * 24 * 36
16 * 25 * 34
16 * 24 * 35

...and that's just minimization.

Update: Now I get an error of ".class expected" for:

if(int input = 0);

Re: Need help with max/min'ing multiply
 

that's to be expected, remove the ;