Which data structure should I use?

[Julia Jin]

Hi, there,

I have a list of elements. Each time when a new data comes in, I need
to check if the new data exists in the list. If not exists, I need to
insert the new data into the list.

If I keep the list unsorted, when the length of the list becomes
large, it takes a long time to check if an elements exists in the list
or not.

In this case, which data structure should I use? Can anyone give me
some suggestion or a short piece of C code? Thanks!

Julia

 

[Ema]

Hi, there,

I have a list of elements. Each time when a new data comes in, I need
to check if the new data exists in the list. If not exists, I need to
insert the new data into the list.

If I keep the list unsorted, when the length of the list becomes
large, it takes a long time to check if an elements exists in the list
or not.

In this case, which data structure should I use? Can anyone give me
some suggestion or a short piece of C code? Thanks!

It depends:
- on the type of your data
- (if your data are record (struct)) on the kind of existence check (on all
the record, on one particular field, ...)

You can try hash tables:
- as alternative data structure to lists
- as auxiliary "existence check" data structure, to use together with lists

I apoligize for my bad English... :-(

Ciao,
Ema