CODEWITHSUNDEEP
cdata-structures
goldenmean
goldenmean

Reputation: 19026

What data structure suits for this data

This is my work but not home work. I am trying to come up decide how best to represent a data I have using a native data structure(By native i mean I cannot use STL in C++, its a C++ code. Its our design decision not to use STL and have no way to change it or violate it)

Data is as follows:

There is a variable say int to denote ipaddr say e.g. 192.168.10.77(lets say this is stored in a int which is uniquely obtained from the 192.168.10.77 ) which lets call deviceId.

Now for each such deviceId there are other fields multiple services associated to it say service 1, service2, etc... Number of services associated with each device is variable from one deviceId to another.

So a sample of data could look like:

192.168.10.77 

    service1

    service2

    service3

    service4

192.168.10.98

    service1

    service2

192.168.10.97

    service1

Right now I store it in a inefficient data structure as below.

I have a struct as:

typedef struct
{
   deviceId d;
   serviceId s;
}mystr;

And then I use an array of a struct which holds 

mystr mylist[64];

so entries of this array look like

mylist[0].d = 192.168.10.77

mylist[0].s = service1


mylist[1].d = 192.168.10.77

mylist[1].s = service2

mylist[2].d = 192.168.10.77

mylist[2].s = service3

mylist[3].d = 192.168.10.77

mylist[3].s = service4

mylist[4].d = 192.168.10.98

mylist[4].s = service1

mylist[5].d = 192.168.10.98

mylist[5].s = service2

... ... and so on ....

Essentially the deviceId value is duplicated as many times as there are services associated to it.

I need some thing more efficient because later I have to group all the services associated with a device.

So to do that I might have to search for deviceId and club the services for it together. I don't know how I am going to search by deviceId as it can have any value.

What is a better way to represent this data using some optimal data structure ?

[ I can see it as linked list but could not come up with the struct Node{ } for it ]

Upvotes: 2

Views: 198

Answers (4)

rohitmb
rohitmb

Reputation: 151

You can have link list of devices with link list of services

typedef Service{
 serviceId s;//store service id
 Service *nextService;//link to the different services supported by the device, end by null
}*deviceServiceList;

typedef struct Device{
 deviceId d;//store the device id
 Service *s;//store the list of service available for this device
}myDevices;

the devices can be stored in a array of devices or u can create a link list of devices

Upvotes: 0

Pannan Mp
Pannan Mp

Reputation: 77

typedef struct
{ deviceId d;
serviceId s[100]; more than 1 service for 1 device is required

 `}mystr;  

mystr mylist[64];`

or you can have a linked list like

` struct device {
device id; *service; }

 typedef struct serviceid{
 {
   *service;
 }service;

` point to null by last service id

Upvotes: 2

Matt Browne
Matt Browne

Reputation: 12429

How about this library to store it as a basic hash table?

http://troydhanson.github.com/uthash/

Disclaimer: I'm only vaguely familiar with C

Upvotes: 0

john.pavan
john.pavan

Reputation: 950

Consider using gethostbyname and gethostbyaddr. First try one, if it fails, try the other. Then you only have to store one string.

Upvotes: 0

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