// dstack.h -- Dynamic stack (DStack) declaration and function prototypes.  
//
// Functions:
//
//      init(S, int N)          initalized stack of size N
//      push(S,val)             push new value on top of stack
//      pop(S)                  returns (and removes) top value of stack
//      num_items(S)            returns number of items currently on stack
//      size(S)                 returns max number of items stack can hold
//      full(S)                 returns 1 if stack is full, 0 otherwise
//      empty(S)                returns 1 if stack is empty, 0 otherwise
//      cout << S               print stack contents 
//      remove(S)               release memory utilized by stack
//

typedef struct
{
    float *bottom;
    float *top;
    int size;
} DStack;

void init(DStack &S, int size);
void remove(DStack &S);
void push(DStack &S, float val);
int num_items(const DStack &S);
float pop(DStack &S);
int full(const DStack &S);
int empty(const DStack &S);
ostream& operator<<(ostream &os, const DStack &);