C / C++ / MFC

2-Mar-09 5:58

[Message Deleted]

Richard Andrew x642-Mar-09 6:12

2-Mar-09 6:12

Sounds like a homework problem. Unsure | :~

Anyway, could you describe exactly what the difference between the two formats is?

Ric Ashton2-Mar-09 6:31

Ric Ashton

2-Mar-09 6:31

You need to state exactly what type of format or organising structure you are trying to acheive.

Ric Ashton2-Mar-09 6:33

Ric Ashton

2-Mar-09 6:33

Are you trying to just get rid of the duplicated record?

Davitor2-Mar-09 6:45

2-Mar-09 6:45

It's my problem man.I don't what rid problem and what he want to do..If you have some idia then plz help me

Davitor2-Mar-09 6:42

2-Mar-09 6:42

i need remove duplicate values..

Eytukan2-Mar-09 6:56

2-Mar-09 6:56

You can use "std::unique" algo, but you will have to design your own class with overloads to support it.

Example[^]

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Ric Ashton2-Mar-09 6:59

Ric Ashton

2-Mar-09 6:59

Then in any environment, you need to qualify what you wish to discard.
You need to place a field (that you specify) into a list box and disallow
the duplication of a matching field. If the field or database.component is
new then allow the record to be copied to a new file.
At the end (after testing) simply replace your old file with the new one.
I'm assuming your running a few thousand records.

Richard Andrew x642-Mar-09 7:44

2-Mar-09 7:44

Ric Ashton wrote:
I'm assuming your running a few thousand records.

Don't be so generous. This is obviously a homework assignment.

Maximilien2-Mar-09 6:53

Maximilien

2-Mar-09 6:53

1- create a structure (or class) that contains the fields for each record ; create/use a collection that holds your records
2- in a loop :
3- read one line of the file, knowing that you know the format, you can skip unwanted lines.
4- skip line if unwanted; if line contains (is?) "============" and it's the first one, then you know it's a
new record.
5- read the next few lines to fill a record.
6- look in your collection to see if new record is already there; if it's not there, add it to your collection.
7- once you've read all the lines,
8- write back the data line-by-line in a new file.

(steps 5,6 can be optimized to not have to create a new record until you've find if the item is not in the collection).

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Davitor2-Mar-09 7:05

2-Mar-09 7:05

Thanks sir your logic is to much sound.Can you give me some dummy code.Plz help me

Maximilien2-Mar-09 7:16

Maximilien

2-Mar-09 7:16

I will not give you code (dummy or not); I want you to try to come up with a solution based on the suggestions we've given you.
Once you've tried one, two, or even more solutions to your problem (which sounds like a homework), and you still
have problems, then we will gladly be of help of precise problems you can still have.

It can be also easier to ask questions to your teachers and/or teaching assistants and/or computer lab assistants;
or even fellow students.

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Constructor / Destructor Question

David Crow2-Mar-09 9:01

David Crow

2-Mar-09 9:01

The first order of business would be to read the data into some sort of data structure. Until you can get that far, eliminating duplicates is irrelevant.

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Richard Andrew x642-Mar-09 5:15

2-Mar-09 5:15

Given the struct declaration thus:

struct TestStruct
{
    CObject   obj[ 20 ];
};

If I say,

TestStruct *ts = new TestStruct;

Does the CRT call the constructors for any of the CObject's, either all of them, or just the first one in the array?

And does the same answer apply to calling the destructors when I delete ts ?

«_Superman_»2-Mar-09 5:31

«_Superman_»

2-Mar-09 5:31

All 20 CObject default constructors will be called on creation.
Destructors will also be called on destruction.

«_Superman_»
I love work. It gives me something to do between weekends.

Richard Andrew x642-Mar-09 6:10

2-Mar-09 6:10

Thanks for the reply. I am surprised, actually. I did not expect that all of them would be called.

Eytukan2-Mar-09 6:42

2-Mar-09 6:42

They are all allocated on the stack & so gets cleaned automatically. You are almost nearly talking about something like this :

struct TestStruct
{
    CObject*   pObj;
 TestStruct()
 {
   pObj = new CObject[20];
 }
};

Then in the dtor you'll have to manually delete all the cobjects.

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Perisic, Aleksandar2-Mar-09 7:37

Perisic, Aleksandar

2-Mar-09 7:37

Don't confuse it all.

Assume we have

struct TestStruct{    
CObject   obj[ 20 ];
};

// everything is on the stack
{
TestStruct ts; // TestStruct constructor and 20 CObject constructors called

} // TestStruct destructor and 20 CObject destructors called
// nothing to delete, no memory leak

{
// everything is on the heap, ts and with that 20 CObject's
TestStruct *ts = new TestStruct; // TestStruct constructor and 20 CObject constructors called

// everything is destroyed 20 CObjects's and ts
delete ts; // TestStruct destructor and 20 CObject destructors called
}

{
// everything is on the heap, ts and with that 20 CObject's
TestStruct *ts = new TestStruct;

// no delete
}
// memory leak

Richard Andrew x642-Mar-09 7:39

2-Mar-09 7:39

Thanks for clearing that up.

I was confused as well.

Eytukan2-Mar-09 19:34

2-Mar-09 19:34

I think I'm not confused.
Here[^]

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Eytukan2-Mar-09 19:32

2-Mar-09 19:32

struct TestStruct{    
CObject   obj[ 20 ];
};

Didn't you notice I changed my example to

struct TestStruct{    
CObject*   pobj; //Pointer.
TestStruct()
{
 pObj = new CObject[20];
}
};

?
I was trying to give an example where the destructors of the CObjects wouldn't be called. What am I confusing here? Whatever may be the creating type of the TestStruct object, heap or stack, here in my example, it's going to create all the CObjects in heap.
I'll explain you better. Suppose Now you create an object of TestStruct:

TestStruct obj; //Here the object is on stack. But all CObjects would in the heap.

So in the destructor we have to manually delete them all.

~TestStruct()
{
 delete[] pObj;
}

That's what I explained. May be you didn't get my context.

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Perisic, Aleksandar2-Mar-09 19:54

Perisic, Aleksandar

2-Mar-09 19:54

Easy, man! We are just talking here.
Just to be safe, I explained it all relevant to the question.
From your initial post, it was not totally clear that you meant this what you have shown here, and it is a different example from what was asked, so I just wrote it all out using the same code pattern from the initial question to avoid any possible confusion, because everything is fine as long as the person who asked the question got the right understanding not you or me. Big Grin | :-D

Eytukan2-Mar-09 20:03

2-Mar-09 20:03

lol sorry for the vote there. knee-jerk reaction Big Grin | :-D

. restored it. Thumbs Up | :thumbsup:

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Richard Andrew x642-Mar-09 7:38

2-Mar-09 7:38

I would expect them to be allocated on the stack IF my ts variable were a stack-based variable. But if you check my original post, you'll see that ts is allocated on the heap with new.

Are you saying that even though ts is created on the heap, that the CObject array inside the structure is created on the stack? Unsure | :~

Eytukan2-Mar-09 19:46