stack.h

这是栈的顺序实现方法,适合数据结构的初学者参考.

#include<iostream>
#define maxstack 10

using namespace std;

enum Error_code{success,overflow,underflow};
typedef char Stack_entry;

class Stack {
public:
	Stack();
	void clear();
	int size() const;
	bool full() const;
	bool empty() const;
    Error_code pop();
	Error_code push(const Stack_entry &item);
	Error_code top(Stack_entry &item) const;
private:
	int count;
	Stack_entry entry[maxstack];
};


Stack::Stack()
{
	count = 0;
}

void Stack::clear()
{
	while (count != 0)
		pop();
}

int Stack::size() const
{
	return count;
}

bool Stack::full() const
{
	return count > maxstack;
}

bool Stack::empty() const
{
	return count == 0;
}

Error_code Stack::pop()
{
	Error_code outcome=success;
	if (count==0)
		outcome=underflow;
	else --count;
	return outcome;
}

Error_code Stack::push(const Stack_entry &item)
{
	Error_code outcome=success;
	if (count>=maxstack)
		outcome=overflow;
	else
		entry[count++]=item;
	return outcome;
}

Error_code Stack::top(Stack_entry &item) const
{
	Error_code outcome=success;
	if (count==0)
		outcome=underflow;
	else
		item=entry[count-1];
	return outcome;
}