#include "mydefs1.h"

// Array implementation of stacks. 
// Grow from high index towards 0.

int_stack :: ~int_stack ()
{
		cout << "Deleting stack of size " << sz << endl;
		delete [] stack;
}
void int_stack :: init(int nitems)
{
        sz = nitems;	//specified size
        stack = new int[sz];
        top = sz;
}
void int_stack :: init()
{
        sz = 100;		// default size
        stack = new int[sz];
        top = sz;
}
void int_stack :: push(int x)
{
        assert( !isfull() );
        stack[--top] = x;
}
int int_stack :: pop()
{
        assert( !isempty() );
        return( stack[top++] );
}
bool int_stack :: isempty()
{
        return( top == sz );
}
bool int_stack :: isfull()
{
        return( top == 0 );
}