Re: i want to solve this - C# Discussion Boards

21-Jan-11 22:21

Given these interfaces:
// Simple class that computes a result from two values.
interface IThing {
// Set values from which Result is computed.
void Initialize(int value1, int value2);
int Result { get; }
}
// Contains IThings in named groups.
interface IThingManager {
// Add 'thingToAdd' to group named 'groupName'.
// Create new group 'groupName' if it doesn't exist.
void AddThing(string groupName, IThing thingToAdd);
// Compute sum of all IThings added to group 'groupName'.
int Sum(string groupName);
// Compute sum of all IThings added to all groups.
int TotalSum();
// Output text summary of the IThings contained in this IThingManager.
// (Text can be output using System.Console.WriteLine).
void Print();
}
Write an implementation of the interfaces in these concrete classes:
// Result is the product of value1 and value2, as supplied in the
// ``Initialize`` method.
class MultiplierThing : IThing { ... }
// Result is the sum of value1 and value2.
class AdderThing : IThing { ... }
class ThingManager : IThingManager {
...
// Print: For each group, outputs the sum of the IThings in that group.
// Also output the total sum of all groups.
void Print() { ... }
}
//Inherit VerboseThingManager from ThingManager, and change the functionality of the Print //method to the following:
//1 For each group, output the name of that group, and a list of all members of that group.
//2 Also output the sums like the Print method of ThingManager.
Example Ouput
Given a main program like this:
IThingManager manager = new VerboseThingManager();
IThing t;
t = new MultiplierThing();
t.Initialize(1, 2);
manager.AddThing("Group A", t);
t = new MultiplierThing();
t.Initialize(3, 4);
manager.AddThing("Group B", t);
t = new AdderThing();
t.Initialize(5, 6);
manager.AddThing("Group A", t);
t = new AdderThing();
t.Initialize(7, 8);
manager.AddThing("Group B", t);
manager.Print();
The corresponding output should be:
Group A:
- 2
- 11
Group B:
- 12
- 15
Sum of Group A = 13
Sum of Group B = 27
Total sum = 40

Please Help me
i made the classes of adderthing & MultiplierThing that inherits from interface IThing and stop

Richard MacCutchan21-Jan-11 22:35

Richard MacCutchan

21-Jan-11 22:35

You just need to implement the interface methods as you have defined them. Thus in each class your Initialize() method should store your variables (this could be done in a base class) and your Result() method should return the sum, product, difference etc as appropriate.

I must get a clever new signature for 2011.

Nabawoka21-Jan-11 22:39

21-Jan-11 22:39

i konw but i can't do the implementation of
second interface
interface IThingManager Frown | :(

Nabawoka21-Jan-11 22:55

21-Jan-11 22:55

please i want the implementation of IThingManager Please Smile | :)

Estys21-Jan-11 23:00

21-Jan-11 23:00

I'll give you a partial implementation. Since it's you homework, do the rest yourself.

public class ThingManager : IThingManager
{
    Dictionary<string, List<IThing>> things = new Dictionary<string, List<IThing>>();

    public void AddThing(string groupName, IThing thingToAdd)
    {
        if (!things.ContainsKey(groupName))
        {
            things.Add(groupName, new List<IThing>());
        }

        things[groupName].Add(thingToAdd);

        // Remember that things[groupName] returns a List<IThing> !!
    }
}

Cheers

_{If you can read this, you don't have Papyrus installed}

Nabawoka22-Jan-11 0:02

22-Jan-11 0:02

thaaaaanx alot Estys Big Grin | :-D

but i can't complete because i didn`t deal with collections before
and don`t know how to implement the method sum
how to add items in gruopname
and how to read from user to add in groupname Smile | :)

sorry

Estys22-Jan-11 0:30

22-Jan-11 0:30

Collections are dead easy Smile | :)

The example I gave you already adds things to your group.

To iterate over a collection use foreach :

public int Sum(string groupName)
{
    int retValue = 0;
    foreach (IThing ithing in things[groupName])
    {
        retValue += ithing.Result;
    }
    return retValue;
}

You can do the same for TotalSum. The only difference is to iterate over the things groupNames with KeyValues

Cheers

_{If you can read this, you don't have Papyrus installed}

OriginalGriff22-Jan-11 0:41

OriginalGriff

22-Jan-11 0:41

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

Dave Kreskowiak22-Jan-11 9:03

Dave Kreskowiak

22-Jan-11 9:03

Estys wrote:
If you can read this, you don't have Papyrus installed

I DO have Papyrus installed and can still read it. Now what?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Estys22-Jan-11 11:26

22-Jan-11 11:26

You're just being flippant Smile | :)

_{If you can read this, you don't have Papyrus installed}

Estys21-Jan-11 23:00