count how many time the value appear in the link list -- HELP

hi everyone, i have an error while i compile this code. i tried two diff code but same error...as i know that void function canot return value.. so anyone can help me to fix and return the count number please///

Code:

---


void IPlist::updateCount(string address)
// precondition : address is in list
// postcondition : the count of node with address has been incremented
{

        node* currPtr = list;
        int TotalCount = 0;

        do
        {
                TotalCount++;
                currPtr = currPtr->link;
        }while (currPtr != list);

        return TotalCount;
}

---

Code:

---


void IPlist::updateCount(string address)
// precondition : address is in list
// postcondition : the count of node with address has been incremented
{
    int count = 0;
    node *tmp = list;
    while(tmp != NULL && tmp->IPaddress == address)
    {
        count++;
        tmp = tmp->link;
    }
    return count;
}

---

>void IPlist::updateCount(string address)
To return a value, change void to the type you want to return:

Code:

---

int IPlist::updateCount(string address)

---

do you have any other optioon instead of changing the type as if it could not be change

:)

if you must keep the return type void can you change the parameter list to include a reference to int, ie:

Code:

---

void IPlist::updateCount(string address, int &count)
// precondition : address is in list
// postcondition : the count of node with address has been incremented
{
    count = 0;
    node *tmp = list;
    while(tmp != NULL && tmp->IPaddress == address)
    {
        count++;
        tmp = tmp->link;
    }
}

---

The only other way to return a value from a function by adding a parameter in the function's declaration.

Code:

---

void IPlist::updateCount(string address, int &count)

---

The above would allow you to return an int in count.

how should i call from main

just to make sure cause got errors popping out

ip.updateCount(data[i]);

how many parameters does the updateCount function now require? and what types? take a minute to figure it out :)

ok forget to let you know that the struct type

Code:

---

struc node(
{
    string IPaddress;
    int count;
    node * link;
}

---

which means that we count the number of occurences and display it ,,,

here is the class file

Code:

---


#ifndef IPLIST
#define IPLIST

#include <iostream>
#include <cstdlib>
using namespace std;

struct node
{
  string IPaddress;
  int count;
  node *link;
};

class IPlist
{
  // contains an ordered list of IP addresses and a count of each
  // occurrence
  public:

    IPlist();  // default constructor
              // creates a new empty list

    ~IPlist(); // destructor - reallocates all dynamic memory of list

    IPlist (const IPlist & other);
              // copy constructor to create a deep copy of other IPlist
              // object

    bool empty() const;
              // precondition : none
              // postcondition : returns true if list is empty
              //                and otherwise false

    void insertInOrder(string address);
              // precondition : list is ordered and address is not in list
              // postcondition : list is ordered and contains address

    bool isPresent(string address) const;
              // precondition : none
              // postcondition : returns true if a node containing address
              //                is present in list and otherwise false

    void updateCount(string address);
              // precondition : address is in list
              // postcondition : the count of node with address has been incremented

    node *find (string address) const;
              // precondition : none
              // postcondition : returns a pointer to node containing address or
              //                NULL if not present

    void display() const;
              // precondition : none
              // postcondition : the list has been displayed
              // one record per line, tab-separated
              // with heading IPaddress Count
    private:
   
      node *list;
};
#endif

---

im kind of confused about the count. does this list contain duplicate IP addresses? if so, why is there a need to have duplicates?

can you explain what the class in general is to do and this updateCount function in particular, then i can try and help.

edit: i read your comments in the code so please dont just repeat those, if you can

i am sorry..

i try to explain...

the updatecount is to update how many duplicate ip address in the list...
tats all it does....

better explanation

u just
increase count by one (if found duplicate) otherwise you 'put in' the new address......

hope it helps u

as i asked in previous post, do you WANT to allow duplicates? if this is an ordered list, how do you determine what duplicate is 'first' before another duplicate?

if you have a duplicate then you will have 2 identical nodes, correct? ie, 2 nodes with same ip address and same count (2), right?

i think you should either get rid of the count or get rid of the duplicates.. or is there a better reason you need duplicates and count that i dont see? or is this some project which REQUIRES it?

yes, it is requirement. and yes this list will containt duplicate and
for example
input file is

192.149.089.061
100.001.004.031
034.056.078.012
192.149.089.061
100.001.004.031
192.149.089.061
111.022.033.004
192.149.089.061
111.022.033.004
111.022.033.004

and the output will be

IpAddress Count
------------- --------
192.149.089.061 4
100.001.004.031 2
034.056.078.012 1
111.022.033.004 3

from the looks of the output there are only 4 NODES that you create (or at least print).

i dont understand if you want duplicate NODES (notice i said nodes not ip addresses), AND you want to count how many times each node occurs, even with duplicates..

the output you shown is not containing duplicate NODES but duplicate ipaddresses, if it had duplicate nodes and you incremented each count appropriatly, the output would be:

IpAddress Count
------------- --------
192.149.089.061 4
192.149.089.061 4
192.149.089.061 4
192.149.089.061 4
100.001.004.031 2
100.001.004.031 2
034.056.078.012 1
111.022.033.004 3
111.022.033.004 3
111.022.033.004 3

i hope im making sense. i think the solution is to get rid of duplicate nodes. when you add another ip address, then ,as you have in the updateCount function, search your list for the new ipaddress and increment that node's count.. you dont need to create another node.

or is what im saying still not satisfy the requirement of needing duplicate NODES. realize in this case duplicate nodes are just that.. 2 nodes with EXACTLY the same data, it doesnt make sense to me.

im off to bed, ill check back in the morning.

thanks and i will try to explain it clearly ... please check error when u have time alright .. appreciate tat... can you send me ur emaill addresss as i want to send you whole the cpp and it might easier for you to understand

i think you are right..
so what you mean is that the display function is miss coded right?
i dont know where should i correct it in order to get the output as wat i mention above...

anyone please help ....i really need to finsih this up now... h help :(

id rather communicate here because: its permanent (or almost!), its public (so others can help and learn), and you can post your full code here with code tags for nice formatting.


i dont think anythings wrong with your display function. please reread my previous response to see if it makes any other sense to you... i think you just need ONE node PER ip address. if you have a duplicate ip address, then increase that node's count variable.

i dont see why you want to have duplicated nodes. (note: i said duplicated NODES not IP addresses)

back in the morning! good luck

Quote:

---

Originally Posted by nadroj

im kind of confused about the count. does this list contain duplicate IP addresses? if so, why is there a need to have duplicates?

can you explain what the class in general is to do and this updateCount function in particular, then i can try and help.

edit: i read your comments in the code so please dont just repeat those, if you can

---

this list will contain duplicate address. it cannot be change cause is a part of work....

ok here is the explanation of overall work ...

<this program reads these IP addresses from a file and stores them in a linked list where each node will store the addresses and the number of times that address appears in the data file. list will be ordered in ascending order by IP address...As each address is read the program showuld check if it is already in the list. if it is then its count should be incremented by 1. if it isnt alreadyy int the list . should be inserted into the list so as to maintain the ordering of the list.


the display will look like

Please look at the list display

i still think from this description it is not requiring duplicate NODES. your not realizing that a NODE DOES NOT EQUAL IP ADDRESS.

PLEASE read this. i will repeat it from a previous post, this is how your looking at how the output should be:

Input File
--------------------------
192.149.089.061
100.001.004.031
034.056.078.012
192.149.089.061
100.001.004.031
192.149.089.061
111.022.033.004
192.149.089.061
111.022.033.004
111.022.033.004

IpAddress Count
--------------------------
192.149.089.061 4
192.149.089.061 4
192.149.089.061 4
192.149.089.061 4
100.001.004.031 2
100.001.004.031 2
034.056.078.012 1
111.022.033.004 3
111.022.033.004 3
111.022.033.004 3

this IS how it would look if you had duplicate NODES. you dont want duplicate nodes, you want duplicate IP ADDRESSES. a duplicate ip address is simply a node whose ip address has appeared 1+ times (which is stored in it's count variable).
this is how the output would appear if you dont have duplicate nodes (note you still have duplicate ip addresses):

Input File
--------------------------
192.149.089.061
100.001.004.031
034.056.078.012
192.149.089.061
100.001.004.031
192.149.089.061
111.022.033.004
192.149.089.061
111.022.033.004
111.022.033.004

IpAddress Count
--------------------------
192.149.089.061 4
100.001.004.031 2
034.056.078.012 1
111.022.033.004 3


are we on the same page yet?

You state in the preconditions to that function that a node with that address has to exist, so why do you create a new one ?.
If you really want to create a new node then you would have to remove the old one from the list and replace it with the new one.
Kurt

hi Zuk, well is not has to exist.... is <if exist, increment the count .....>

I'm not talking about the overall logic. I'm talking about the precondition to the function updateCount().
If exitance of the address is a precondition then updateCount() must not be called if the address doesn't exist. So according to the stated predcondition updateCount() has to find the node containing that address and simply increment its count member. No need to create a new node.
BTW: the way your function works now you would create a memory leak because you don't free the old node and you don't link the new node into the list.
Kurt

I was thinking about something like this

Code:

---

void IPlist::updateCount(string address )
// precondition : address is in list
// postcondition : the count of node with address has been incremented
{
  // no checks for 0 necessary, we know that it must be somewhere
    node *tmp = list;
    while( tmp->IPaddress != address)
        tmp = tmp->link;
    tmp->count++;
}

---

Kurt

thnx, the code is fine.. but the output is like this

IP address count
034.056.078.012 3998072
100.001.004.031 3998073
111.022.033.004 3998074
192.149.089.061 3998100

which is not right .. DAMN... :'(

i was thinking the same too but that isnt work for me as well ...

How do you create new nodes ? Looks like count is not initialized to 1 when a new node is created.
Kurt

where should i initialize count to 0 ???in the private of the class??

I think that the main code has a logical error also - else is missing see my comment inside your code

Code:

---

while(myFile>> filename)
 {
        if(ip.empty())                        // store IP address into link list
        {
            ip.insertInOrder(filename);
        }       
       //else is missing
        //because we inserted the new node IP address is already present
        //we will update the count for the first node - it is wrong
      if (!ip.isPresent(filename))      // if no duplicate ip address
      {
                          ip.insertInOrder(filename);    // we insert the ip address into link list
      }
      else
      {
                ip.updateCount(filename);      // otherwise we add one to the count
      }
 }
 ip.display();

---

Quote:

---

where should i initialize count to 0 ???in the private of the class??

---

in the fuction insertInOrder you probably create new node.
you should initialize all its members, including count

Logically - at the beggining count should be set to 1 because it is the first occurence of this ip

Quote:

---

Originally Posted by vart

in the fuction insertInOrder you probably create new node.
you should initialize all its members, including count

Logically - at the beggining count should be set to 1 because it is the first occurence of this ip

---

so wat you mean is
initialize list in the insertinorder???

do you mean in the default constructor??

I mean count should be set to 1 not 0 at the beggining - this will fix your output to
IP address count
034.056.078.012 1
100.001.004.031 2
111.022.033.004 3
192.149.089.061 5

I suppose the 192.149.089.061 was the first ip entered.
look at my comment about missing else - this will fix 5 to 4

Quote:

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do you mean in the default constructor??

---

I mean here:

Code:

---

void IPlist::insertInOrder(string address)
// precondition : list is ordered and address is not in list
// postcondition : list is ordered and contains address
{
    node *tmp = new node;
    tmp->IPaddress = address;
    tmp->count=1;...

---

Quote:

---

Originally Posted by vart

I mean count should be set to 1 not 0 at the beggining - this will fix your output to
IP address count
034.056.078.012 1
100.001.004.031 2
111.022.033.004 3
192.149.089.061 5

I suppose the 192.149.089.061 was the first ip entered.
look at my comment about missing else - this will fix 5 to 4

---

yes the overall output is correct but the last ip address suppose to be 4//...
i mean count 4 instead of 5

wat do you mean by this vart
I suppose the 192.149.089.061 was the first ip entered.
look at my comment about missing else - this will fix 5 to 4

read my comment #28 in this thread

>>yes the overall output is correct but the last ip address suppose to be 4//...
i mean count 4 instead of 5

This type of problem frequently occurs because of the wrong condition used in a loop to read in the file. If you have something like this:

while(! ifstreamName.eof())

instead of something like

while (ifstreamName >> variableName)

or this

while(ifstreamName.getline())

then you get the innappropriate result because the last item from the file can behave as if it were being read in twice. Posting the code that uses a loop to read the file would be helpful if this post doesn't help you check it on your own.