16 replies to this topic

[thedodgeruk]

i know if you do

int[] = new int[100000] ;
thtats ok , but takes a lot of time to create these



i wish to just use

int[20000] , but its some were between 15000 and 20000 it give an error, is there a way to increase this amount to at least 50,000

[arbitus]

i know if you do

int[] = new int[100000] ;
thtats ok , but takes a lot of time to create these



i wish to just use

int[20000] , but its some were between 15000 and 20000 it give an error, is there a way to increase this amount to at least 50,000

This might be language dependent, but in C#, because the size parameter is of type int, it can only be int.MaxValue.

[Serapth]

What language? In C++, 20K is easily doable, even allocated on the stack.

What specifically is the error.

Frankly int[80000] is only like 1/3 a MB on a 32bit system.

[frob]

int[] = new int[100000] ;
thtats ok , but takes a lot of time to create these

So don't do that.

Figure out what is slow about it. Is it the time taken to allocate the memory? Is it initialization? (Slow initialization is unlikely, but I suppose it is possible if you have a poor processor and are out of memory.) Consider using one of the container classes instead if it makes sense for your situation.

int[20000] , but its some were between 15000 and 20000 it give an error, is there a way to increase this amount to at least 50,000

What is your error, exactly?

I can allocate 500000 just fine on my machine, rather quickly.

[Hodgman]

Are you saying that if you make a large array without using new, then it begins failing with large sizes?
If so, you're probably allocating your array on the stack, which is bad. Large objects should be allocated with new or malloc.

[mind in a box]

If it's slow, have you tried to switch to release mode and to run it without the debugger?

[Serapth]

Here are most default stack sizes.

You can generally increase the size of the stack, but its generally much better/easier to simply allocate on the heap ( aka, new ).

[weka]

I was stupid.

Edited by weka, 12 May 2012 - 06:53 PM.

[Cornstalks]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

[Álvaro]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

That makes no sense. It depends on what you use your array for. The hash table in a chess program is an array with a size of several gigabytes.

To the original question: If you have a hard time defining a large array, you are probably defining it as a local variable (i.e., on the stack). A global array or an array allocated on the heap will allow much larger sizes. If your program takes a long time in something as simple as allocating a smallish array, there's something that needs fixing. Post a short example program so we can see what you are doing. Also, let us know what platform, compiler and compiler settings you are using.

[weka]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

[menyo]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

I don't think thats making any more sense....

[weka]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

I don't think thats making any more sense....

Have you ever seen anyone seen more than 1000 sets in an array? test[1000]

[Cornstalks]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

I don't think thats making any more sense....

Have you ever seen anyone seen more than 1000 sets in an array? test[1000]

Yeah. Have you? What about loading a file into memory? Even if it's only a few kilobytes, it's still a few thousand characters. It's really easy (and not rare at all) to have arrays with lengths more than 1000.

And at any given point in time, applications will often have lots of different arrays. Depending on the application, there can be hundreds of arrays used, each with thousands of elements.

I assume by "sets" you actually mean "elements".

[way2lazy2care]

Have you ever seen anyone seen more than 1000 sets in an array? test[1000]

Not only have I seen it, I have done it.

[weka]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

I don't think thats making any more sense....

Have you ever seen anyone seen more than 1000 sets in an array? test[1000]

I assume by "sets" you actually mean "elements".

Yes, elements.

[menyo]

Honestly, don't even worry about it. The most people use per array, on average, is probably less than five hundred.

What?

Oh, I am sorry. I read that wrong. I thought the NUMBER of arrays.. not the size. My apologies.

I don't think thats making any more sense....

Have you ever seen anyone seen more than 1000 sets in an array? test[1000]

I'm doing [2048*2048] right now....
And need multiple arrays or need to stuff a single one with big structs which would be inneficient for the project i'm currently on.