stack.cpp

顺序栈

#include "stack.h"

Error_code aStack::push (const Stack_entry&item)
{
	Error_code outcome=success;
	if (count>=maxstack)
	{
		outcome=overflow;
	}
	else
		entry[count++]=item;
	return outcome;
}
/***************************************/
Error_code aStack::pop ()
{
	Error_code outcome=success;
	if (count==0)
	{
		outcome=underflow;
	}
	else --count;
	return outcome;
}
/*******************************************/
Error_code aStack::top (Stack_entry&item) const
{
	Error_code outcome=success;
	if(outcome==0)
	{
		outcome=underflow;
	}
	else 
		item=entry[count-1];
	return outcome;
}
/**************************************/
bool aStack::empty() const
{
	bool outcome=true;
	if (count>0)
	{
		outcome=false;
	}
	return outcome;
}
/****************************/
aStack::aStack()
{
	count=0;//initialized the stack
}