Map with struct as key and vector as value Post: 302917423

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Top Forums Programming Map with struct as key and vector as value Post 302917423 by yifangt on Tuesday 16th of September 2014 05:47:39 PM

09-16-2014

Registered User

To make your structure usable in a map, you should define an 'operator <' for it.
How to do so can be fiendishly complex for complicated data, since you first need a coherent definition of what 'less' even means when comparing two student class records.
Definitely I under-estimated the challenge.
Did not realize this only after another two hours of googling/reading. In my original post there were too many errors to be listed here when I tried to compile. which really discouraged me! (Better now.)
Thanks a lot!

---------- Post updated at 05:41 PM ---------- Previous update was at 02:26 PM ----------

Kind of got lost after discussions and searching.
Originally intended output is like:

Code:

---------------------
2333021 Bokow,R. 
                 NS201 3 A
                 MG342 3 A
                 FA302 1 A 
2574063 Failin,D. 
                 MK106 3 C
                 MA208 3 B
                 CP101 2 B
2663628 Kingsley,M. 
                 QA140 3 A 
                 EQ521 3 A
                 MK341 3 A
                 CP101 3 B

So
1) I want student_ID be the key for the courses and names.
2) The records are read from a fstream which contains hundreds of thousands rows, imagine from a university record.
3) Also the student_ID may NOT be clustered together one row after another, so that read in record from file need to be checked for each entry before it is pushed into map.

Last edited by yifangt; 09-16-2014 at 06:47 PM..

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LEARN ABOUT SUNOS

rmfree

rmfree(9F)						   Kernel Functions for Drivers 						rmfree(9F)

NAME

       rmfree - free space back into a resource map

SYNOPSIS

       #include <sys/map.h>
       #include <sys/ddi.h>

       void rmfree(struct map *mp, size_t size, ulong_t index);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       mp	Pointer to the map structure.

       size	Number of units being freed.

       index	Index of the first unit of the allocated resource.

DESCRIPTION

       rmfree() releases space back into a resource map. It is the opposite of rmalloc(9F), which allocates space that is controlled by a resource
       map structure.

       When releasing resources using rmfree() the size and index passed to rmfree() must exactly match the size and index values  passed  to  and
       returned from a previous call to rmalloc(). Resources cannot be returned piecemeal.

       Drivers	may define resource maps for resource allocation, in terms of arbitrary units, using the rmallocmap(9F) function. The system main-
       tains the resource map structure by size and index, computed in units appropriate  for  the  resource.  For  example,  units  may  be  byte
       addresses, pages of memory, or blocks. rmfree() frees up unallocated space for re-use.

       rmfree() can also be used to initialize a resource map, in which case the size and index should cover the entire resource area.

CONTEXT

       rmfree() can be called from user or interrupt context.

SEE ALSO

       rmalloc(9F), rmalloc_wait(9F), rmallocmap(9F), rmfreemap(9F)

       Writing Device Drivers

SunOS 5.10							    4 Jun 2001								rmfree(9F)