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Not repeated elements in link list (help)

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Posts: 17

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lmastex

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Not repeated elements in link list (help)

Dec 4th, 2008

Hi.

I want my Insertion method in my link list class not to insert repeated elements. I have tried several ways but I have seriously ugly bugs in my code:

 Help with Code Tags 
 cplusplus Syntax (Toggle Plain Text) 
template <typename ListElement>
void List <ListElement>::Insert()
{
  NodePtr Ptr;
  Ptr = new Node;
  bool repeated = true;
 
if (Ptr == NULL)
  {
     cout << "Error: Insuficient Storage " << endl;
     exit(1);
  }
 
  cout << " Enter The Social Security Number of New Student: ";
  cin >> Ptr->Info.SSN;
  cout << "Enter The Age of This Student: ";
  cin >> Ptr->Info.Age;
 
	while( Ptr->Next != NULL)
	{
           if(Ptr->Info.Age == Ptr->Next->Info.Age)
             repeated = false;
             break; // This break is for not to add the element
 
             Ptr = Ptr->Next;
 
 
           }
 
Ptr->Next = Head;
  Head = Ptr;
 
if(repeated = false)
 cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works
 
 
 
	}
template <typename ListElement>
void List <ListElement>::Insert()
{
  NodePtr Ptr;
  Ptr = new Node;
  bool repeated = true;

if (Ptr == NULL)
  {
     cout << "Error: Insuficient Storage " << endl;
     exit(1);
  }
  
  cout << " Enter The Social Security Number of New Student: ";
  cin >> Ptr->Info.SSN;
  cout << "Enter The Age of This Student: ";
  cin >> Ptr->Info.Age;
 
	while( Ptr->Next != NULL)
	{
           if(Ptr->Info.Age == Ptr->Next->Info.Age)
             repeated = false;
             break; // This break is for not to add the element
             
             Ptr = Ptr->Next;
         
         
           }
  
Ptr->Next = Head;
  Head = Ptr;
  	
if(repeated = false)
 cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works
 


	}

What do you think it is? Thanks

Last edited by Narue : Dec 4th, 2008 at 2:41 pm. Reason: fixed code tags

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Posts: 665

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Freaky_Chris Freaky_Chris is offline

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

Use code tags please [code=cplusplus][/code]
Also what exactly is the problem?

Chris

Knowledge is power -- But experience is everything

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Posts: 17

Reputation: lmastex is an unknown quantity at this point

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lmastex

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Newbie Poster

Re: Not repeated elements in link list (help)

Dec 4th, 2008

Sorry I forgot ( I remember I used them though) Anyways.
The problem is that when I make an insertion of an element, I don't want to insert a repeated element, so if I inserted (Age = 20) and then If I insert (Age = 20) my list should have only one person who Age is 20, i don't want two ages of 20 in my list. Insertion without repeating elements.

Help with Code Tags

(Toggle Plain Text)

template <typename ListElement>
void List <ListElement>::Insert()
{
NodePtr Ptr;
Ptr = new Node;
bool repeated = true;

if (Ptr == NULL)
{
cout << "Error: Insuficient Storage " << endl;
exit(1);
}

cout << " Enter The Social Security Number of New Student: ";
cin >> Ptr->Info.SSN;
cout << "Enter The Age of This Student: ";
cin >> Ptr->Info.Age;

while( Ptr->Next != NULL)
{
if(Ptr->Info.Age == Ptr->Next->Info.Age)
repeated = false;
break; // This break is for not to add the element

Ptr = Ptr->Next;


}

Ptr->Next = Head;
Head = Ptr;

if(repeated = false)
cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works



}

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Posts: 665

Reputation: Freaky_Chris is a jewel in the rough

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Freaky_Chris Freaky_Chris is offline

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

Here is one method of doing it, get the Age from the user, loop through your linked list. If you find it don't add it to the list if you don't then when add it to the list

Chris

Knowledge is power -- But experience is everything

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cikara21

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

Just call this..

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
bool sample::exist(NodePtr *p,int age)
{
   bool isexist=false;
   NodePtr *n_ptr = p;
   for(;n_ptr!=0;n_ptr=n_ptr->Next)
      if(n_ptr->Info.Age==age)
         isexist=true;
   return isexist;
)
bool sample::exist(NodePtr *p,int age)
{
   bool isexist=false;
   NodePtr *n_ptr = p;
   for(;n_ptr!=0;n_ptr=n_ptr->Next)
      if(n_ptr->Info.Age==age)
         isexist=true;
   return isexist;
)

$.:-cikara21-:.$

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Laiq Ahmed Laiq Ahmed is offline

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

•

Originally Posted by lmastex

Sorry I forgot ( I remember I used them though) Anyways.
The problem is that when I make an insertion of an element, I don't want to insert a repeated element, so if I inserted (Age = 20) and then If I insert (Age = 20) my list should have only one person who Age is 20, i don't want two ages of 20 in my list. Insertion without repeating elements.
Help with Code Tags

(Toggle Plain Text)
template <typename ListElement>
void List <ListElement>::Insert()
{
NodePtr Ptr;
Ptr = new Node;
bool repeated = true;

if (Ptr == NULL)
{
cout << "Error: Insuficient Storage " << endl;
exit(1);
}

cout << " Enter The Social Security Number of New Student: ";
cin >> Ptr->Info.SSN;
cout << "Enter The Age of This Student: ";
cin >> Ptr->Info.Age;

while( Ptr->Next != NULL)
{
if(Ptr->Info.Age == Ptr->Next->Info.Age)
repeated = false;
break; // This break is for not to add the element

Ptr = Ptr->Next;


}

Ptr->Next = Head;
Head = Ptr;

if(repeated = false)
cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works



}
template <typename ListElement> void List <ListElement>::Insert() { NodePtr Ptr; Ptr = new Node; bool repeated = true; if (Ptr == NULL) { cout << "Error: Insuficient Storage " << endl; exit(1); } cout << " Enter The Social Security Number of New Student: "; cin >> Ptr->Info.SSN; cout << "Enter The Age of This Student: "; cin >> Ptr->Info.Age; while( Ptr->Next != NULL) { if(Ptr->Info.Age == Ptr->Next->Info.Age) repeated = false; break; // This break is for not to add the element Ptr = Ptr->Next; } Ptr->Next = Head; Head = Ptr; if(repeated = false) cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works }

I've changed your code

 Help with Code Tags 
 cpp Syntax (Toggle Plain Text) 
template <typename ListElement>
void List <ListElement>::Insert()
{
NodePtr Ptr;
Ptr = new Node;
bool repeated = false;
 
  if (Ptr == NULL)
 {
    cout << "Error: Insuficient Storage " << endl;
    exit(1);
 }
 
  cout << " Enter The Social Security Number of New Student: ";
  cin >> Ptr->Info.SSN;
  cout << "Enter The Age of This Student: ";
  cin >> Ptr->Info.Age;
 
 while( Ptr->Next != NULL)
 {
      if(Ptr->Info.Age == Ptr->Next->Info.Age) {
          repeated = true; 
          break; 
     }
     // This break is for not to add the element
     Ptr = Ptr->Next;
  }
 
 if(repeated = false) {
    Ptr->Next = Head;
    Head = Ptr;
 }
  else { 
          delete Ptr;
          cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works
   }
template <typename ListElement>
void List <ListElement>::Insert()
{
NodePtr Ptr;
Ptr = new Node;
bool repeated = false;

  if (Ptr == NULL)
 {
    cout << "Error: Insuficient Storage " << endl;
    exit(1);
 }

  cout << " Enter The Social Security Number of New Student: ";
  cin >> Ptr->Info.SSN;
  cout << "Enter The Age of This Student: ";
  cin >> Ptr->Info.Age;

 while( Ptr->Next != NULL)
 {
      if(Ptr->Info.Age == Ptr->Next->Info.Age) {
          repeated = true; 
          break; 
     }
     // This break is for not to add the element
     Ptr = Ptr->Next;
  }

 if(repeated = false) {
    Ptr->Next = Head;
    Head = Ptr;
 }
  else { 
          delete Ptr;
          cout << "repetition just ocurred" << endl; // This is just 4 me to verified if the function works
   }

Hope Above idea helps

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Posts: 17

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lmastex

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

If there is a break in line 23 to stop the element to be added, then why is line 34 is a deletion?

(Im having problems with the code "cpp Syntax" changed)

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Posts: 113

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Laiq Ahmed Laiq Ahmed is offline

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Re: Not repeated elements in link list (help)

Dec 4th, 2008

because You allocated the element on Heap in the beginning and you should release its memory if its a repeated element otherwise you'd have a memory leak.