Stacks?

A stack is kind of like a pile of dishes:

When you put one on, that will be the first taken off:

3rd put on.
2nd put on.
1st put on.

As you can see, the third is on top.

Push something onto stack:

4th put on.
3rd put on.
2nd put on.
1st put on.

Pop something off the stack:
stack:                      Value returned:

3rd put on.               4th put on.
2nd put on.
1st put on.

[factor777]

ok thats a bit more clearer now.
what would be the purpose of such a way as stacking?
I just would not know waer to apply this method too.

would it be used around true conditions or what?

[parksie]

Stacks are useful for recursion. To totally understand how they apply to this you need to know how C uses return values. The return value is stored in the register EAX on the processor. Each time you call the function, it pushes it onto a stack, so that you "unwind" the stack to go back through the functions collecting the return values in order.

stacks in general as a data structure.

[parksie]

The STL has a stack template.

[HarryW]

STL has a lot of handy templates doesn't it? A list template too, if I remember. I don't suppose there's a tree template too? And a queue?

[parksie]

I don't think it has a specific tree, but you can get make one by using list<list<int> > or similar (remembering the space between > and >).

There is a queue, and also something called priority_queue which is a sorted queue.

[HarryW]

Cool. Easier to make your own tree class I think. Any other natty ADTs that the STL provides that I should know about?