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Contact Manager Linked List Help

Contact Manager Linked List Help, Help With linked list

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riskyricky	15 Oct, 2008 - 10:56 AM Post #1
New D.I.C Head Joined: 30 Sep, 2008 Posts: 5	I Have created a Contact manager that stores contacts along with other information. I used a fixed size array, and need help changing program into a linked list. I also need help creating a search function. This function would let the user search the contacts by name, phone, address, etc. How would i get the function to search each list. My program code is: CODE /* In this program we create a contact manager to manage three total contacts, by student ID. Includes phone number GPA and Hours./ #include <stdio.h> enum kind {GPA, HOURS} kind; struct student{ union grade { int hours; double gpa;} grade; int kind; int id; struct phone{ int area; int pre; int suf;} phone; }; int main (int argc, char *argv){ int entry, i; struct student stu[3]; char gh; int num = 0; do{ printf("[1] Enter a new Contact \n"); printf("[2] Display the Contacts \n"); printf("[3] Quit\n\n"); printf("Enter 1 - 3: "); scanf("%i", &entry); switch(entry){ case 1: printf("Enter a Student ID number:\n900"); scanf("%i", &stu[num].id); printf("[G] Enter GPA:\n"); printf("[H] Enter number of completed Hours\n"); scanf(" %c", &gh); switch(gh){ case 'G': stu[num].kind = GPA; printf("GPA: "); scanf(" %lf", &stu[num].grade.gpa); break; case 'H': stu[num].kind = HOURS; printf("Hours: "); scanf(" %i", &stu[num].grade.hours); break; default: printf("Incorrect entry\n"); } printf("Enter the phone number (###) ###-####\n"); scanf(" (%i) %i-%i", &stu[num].phone.area, &stu[num].phone.pre, &stu[num].phone.suf); num++; break; case 2: for(i = 0; i<num; i++){ printf("ID: 900%i\n", stu[i].id); if(stu[i].kind == GPA){ printf("GPA: %lf\n", stu[i].grade.gpa); } else if(stu[i].kind == HOURS){ printf("Hours: %i\n", stu[i].grade.hours); } printf("Phone: (%i) %i-%i\n", stu[i].phone.area, stu[i].phone.pre, stu[i].phone.suf); } break; case 3: printf("Thank You for using MyContactManager\n"); break; default: printf("Entry not acceptable\n"); } } while(entry < 3); return (0); } Any help greatly Appreciated. Thanks!
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ajwsurfer	RE: Contact Manager Linked List Help 16 Oct, 2008 - 06:27 AM Post #2
D.I.C Regular Joined: 24 Oct, 2006 Posts: 292 Thanked: 2 times Dream Kudos: 50 My Contributions	Here are some tutorials for a singly linked list (from a Google search on "linked list tutorial"). Adding a search function to this should be fairly trivial. Just make a function that does a loop or recursion, to check one of the members of each struct contained in the list. http://richardbowles.tripod.com/cpp/linklist/linklist.htm http://www.fortunecity.com/skyscraper/fals...0/linklist.html
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David W

RE: Contact Manager Linked List Help
16 Oct, 2008 - 07:19 AM

Post #3

D.I.C Regular

Joined: 20 Sep, 2008
Posts: 315

Thanked: 16 times
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My Contributions

cpp

// template class List //

template< class T >
class List
{
public:
    List();
    ~List();
    void addpre( T e );
    void append( T e );
    void addafter( int c, T e );
    void scratch( T e );
    void show();
    bool has( T e ) const; // this can be a start on your 'search'
    int length() const;
    T List<T>::max();    // you don't need this 
    T List<T>::min();    // nor this ...
private:
     struct node
    {
        T data;
        node *link;
    }*p;
};

template< class T >
List<T>::List()
{
    p=NULL;
}

template< class T >
List<T>::~List()
{
   node *q;
   if( p == NULL )
      return;

   while( p != NULL )
   {
      q = p->link;
      delete p;
      p = q;
   }
}

template< class T >
void List<T>::addpre(T num) // inserts num with type T at front of List
{
   node *b;
   b = new node;
   b->data = num;
   b->link = p;
   p = b;
}

template< class T >
void List<T>::append(T num) // inserts num with type T at end of List
{
    node *end,*tmp;
    
    if(  p == NULL  )
    {
        p = new node;
        p->data = num;
        p->link = NULL;
    }
    else
    {
        end = p;
        while( end->link != NULL )
            end = end->link;
        
        tmp = new node;
        tmp->data = num;
        tmp->link = NULL;
        end->link = tmp;
   }
}

template< class T >
void List<T>::addafter( int c, T num) // inserts num with type T after index c
{
   node *q,*t;
   int i;
   for(i=0,q=p;i<c;i++)
   {
      q = q->link;
      if( q == NULL )
      {
         cout << "\nThe highest index allowed is " << i 
              << " and that is less than requested index " << c << ".";
         cout << "\nAppend y/n ? "; 
         string reply;
         getline( cin, reply );
         if( reply[0] == 'n' || reply[0] =='N' ) return;
         q = p;
         while( q->link != NULL )
            q = q->link;
         
         break;
      }
   }

   t = new node;
   t->data = num;
   t->link = q->link;
   q->link = t;
}

template< class T >
void List<T>::scratch( T e )
{
   node *q,*r;
   q = p;
   if( q->data == e )
   {
      p = q->link;
      delete q;
      return;
   }

   r = q;
   while( q!=NULL )
   {
      if( q->data == e )
      {
         r->link = q->link;
         delete q;
         return;
      }

      r = q;
      q = q->link;
   }
   cout<<"\nElement "<< e <<" not Found.";
}

template< class T >
void List<T>::show()
{
   node *q;
   for( q = p; q != NULL; q = q->link )
        cout<<endl<<q->data;
   cout << "\n\nPress 'Enter' to continue ... ";
   cin.clear();
   cin.sync();   
   cin.get();
}

template <class T>
bool List<T>::has( T e ) const
{
    node *q;
    q = p;  
    while(q != NULL)  
    {  
        if(q->data == e )  
            return true;  
        else  
            q = q->link;  
    }  
    return false;    
}

template <class T>
int List<T>::length() const
{
    node *q;
    int c=0;
    for( q=p; q != NULL; q = q->link )
        c++;
    return c;
}

template <class T>
T List<T>::max()
{
    node *q;
    q = p;
    T max = p->data;

    while(q->link != NULL)
    {
        if( (q->link)->data > max )
            max = (q->link)->data;
            q = q->link;
    }
    return max;
}

template <class T>
T List<T>::min()
{
    node *q;
    q = p;
    T min = p->data;

    while(q->link != NULL)
    {
        if( (q->link)->data < min )
            min = (q->link)->data;
            q = q->link;
    }
    return min;
}]

Maybe you could use/modify this template class List I just submitted to 'snippets' ... Use it to make a list of your objects like this:

cpp

// define your object structure (i.e the fields in each record)
class studentRec
{
public:
    string name; // field 1
    // ...            // field 2
    // ... 
};


int main()
{
    // create an empty fall term list of records ...
    List < studentRec > recFallTerm;
    // now you can append, etc, ... to this list
    //... 
}