Programming

Hi
i have the following structure
struct S
{
char Mod_num[5];
char val[31];
char chr_nm_cd[11];
}
I am reading a 2GB file and inserting into the structure and writing into a vector.
I feel like only vector will be a right option. I tried with multimap but it is memory intensive and hence i dropped multimap.
I have the scenario
1st record
7285
GROZ788Y
SIZE 00513
2nd record
7286
GROZ720Y
SIZEA00678
3rd record
7455
GROZ788Y
SIZE 00565
4th record
7286
GROZ788Y
SIZE 00513
You can observe that 1st and 4th records are the same except for the MOd_num field where the values are 7285 and 7286, they are differing
so i will have the output as
SIZE 00513 GROZ788Y 2 7286 7285
SIZEA00678 GROZ720Y 1 7286
SIZE 00565 GROZ788Y 1 7455

Can you give me a sample program or some directions to solve this.

Are you trying to eliminate duplicates, sort or what?
Using search.h and maybe lsearch() or hsearch() will do what you need. If the data is redundant, hsearch() is not the best choice.

I personally deal with stuff like this by creating an array of pointers, then sorting the array using qsort, which allows one to access an element with bsearch() using a key. Sorting an array of structs is too expensive. But it is not clear what you need.