Stack

[connerrichards95]

I have been asked to create a stack without the use of libraries. I have began the code but having difficulty on creating the rest of it.
<
template <typename T>
class Stack
{
public:

~Stack(void);
void push(T value);
Node<T>* nodePop(void);
T pop(void);
protected:
int count = 0;
Node<T> *pTop = nullptr;
};
>


please can somebody help !!

[mbozzi]

Don't use a linked structure for a stack. It's much easier to use an array, and significantly faster -- much more cache friendly.

You can use operator new[] to create a block of memory, and push objects to the slot at index i++.
You can pop objects off the stack at index --i, and that's essentially it. i, of course, always refers to the next free spot on the stack.

If i is 0, your stack is empty.
When the stack gets too big, allocate a block of memory that's roughly twice as big and copy the old data over to the new block.

However, doing a truly generic data structure correctly is a little bit difficult.
Some questions you may want to ponder, either now or later, once you get this working:
"how do I store a type that can't be default constructed"?
"how do I store a type that can't be copied?"
"how do I store types that can throw exceptions when being moved from (and still provide a strong exception safety guarantee)"?
Maybe there are some more. I don't remember.

Edit: Here's a very rough sketch to get you started:

class my_stack {
private:
  int data[1000] {};
  int i {}; 
public:
  void push(int const val) { data[i++] = val; }
  int pop() { return data[--i]; }
  int peek() const { if (is_empty()) throw "oh no"; else return data[i - 1]; } 
  bool is_empty() const { return i == 0; }
  bool is_full() const { return i == 1000; }
};