What's the difference between DEBUG and BUILD? (CodeBlocks)

[Ardeshir81]

HI!
My question is related to CodeBlocsk and not the C++ itself, BUT I couldn't post in CodeBlock's forum, There was something wrong with Gmail (our government blocked it) so I asked it here.
Believe me I wouldn't asked wrong question in wrong place if I wasn't in a hurry.

My question is that why my program crashes while in "Build and Run mode" BUT it doesn't crash when on "DEBUG" mode.
I am writing a BigInteger program that generates random numbers with random lengths. It crashes while allocating the BigInteger number.
The main problem is that my program includes lots of classes, because I copied the same code that it crahses in another program, BUT in there it didn't crash.
So I think the main problem is that it (the random generated number) is passed to 2 or 3 functions and for 7 or 8's time it crashes.

THANKS in advanced.

[Ardeshir81]

PLEASE!!!! Does anybody know?
Is it necessary that I put my code in here?
It's too long and complicated, that's the reason I didn't put my code.

[ne555]

undefined behaviour is undefined, try to avoid it.
(look for uninitialized variables, out of bounds access, double deletes, dangling pointers)

Try to create a minimal example.
You may debug with optimization enabled.

[Ardeshir81]

Thanks!
BUT I'm not looking for solution to fix it.
I'm wondering what is the difference between DEBG and BUILD?
and what does this exactly mean : "You may debug with optimization enabled."
Thank you in advanced.