Computer Science Canada

dynamic arrays

Author:  Homer_simpson [ Mon Aug 04, 2003 7:58 pm ]
Post subject:  dynamic arrays

i know i can create arrays like this:

int *var;
var = new int[1000];

but how can i create an array with unknown size and add to it whenever i need?

Author:  rizzix [ Mon Aug 04, 2003 9:45 pm ]
Post subject: 

u can't

u might need to use a Vector. i don't know much about vectors in c++. but in java thats what we use.

Author:  Catalyst [ Mon Aug 04, 2003 10:16 pm ]
Post subject: 

well if ur working with something that needs very high speeds (like gfx)
vectors might be too slow for ur needs
another method of making a temporay array and transfering it all over would also be too slow

is there ne more specific that might help in finding the solution that you can provide?

Author:  Homer_simpson [ Mon Aug 04, 2003 11:46 pm ]
Post subject: 

well... there's a method i learned long ago back when i was using pascal... i create a structure hold 3 values : previous,value,next
previous hold the pointer to the previous structure and next hold the pointer to the next and value is the value... i was gonna need arrays to hold my textures... i think this method is gonna work just fine...and i can load new textures at any time...

Author:  rizzix [ Tue Aug 05, 2003 12:41 am ]
Post subject: 

btw the method ur talking about is known as LinkedLists, i'm not sure if it is a lot more faster. but i'm pretty sure vectors are pretty fast. you could modify the buffer size of the vector to improve performance

Author:  Homer_simpson [ Tue Aug 05, 2003 1:31 am ]
Post subject: 

can u explain to me how vectors work?

Author:  Catalyst [ Tue Aug 05, 2003 4:02 pm ]
Post subject: 

linked lists should be fine for textures (i thought u might be using them for verticies and such where they would be far too slow)

if u want to save ur self some trouble u can use the standard list class
std::list it has a lot of good features and is painless to implement

Author:  Homer_simpson [ Tue Aug 05, 2003 8:21 pm ]
Post subject: 

yes but i am still interested in knowing about vectors...

Author:  Catalyst [ Tue Aug 05, 2003 9:09 pm ]
Post subject: 

http://www.msoe.edu/eecs/ce/courseinfo/stl/vector.htm

Author:  Homer_simpson [ Tue Aug 05, 2003 10:37 pm ]
Post subject: 

ah... ic...TY for the link man...


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