第四次实验参考代码

参考代码

#include <iostream.h>
#include <stdlib.h>
#include <time.h>
#define NULL 0

struct SNode{
	int data;
	SNode *next;
};

class Stack{
public:
	Stack();
	~Stack();
	void Push(int e);      //insert a data into stack
	int Pop();        //delete a data from stack
	int GetTop();  //Get the data of Stack Top
	int Empty();    //Judge the Stack empty or not
	friend int GetSum();  //get sum of stack,friend function
    //friend class getsum;// get sum of stack,friend class
	static int num;   //static number
private:
	SNode *Head;
};

int Stack::num=0;

Stack::Stack()
{
	Head=new SNode;
	Head->next=NULL;
}

Stack::~Stack()
{
	delete Head;
}

void Stack::Push(int e)
{
	SNode *p,*q;
	if(!(p=new SNode))
		exit(0);
	p->data=e;
	q=Head;
	while(q->next)
		q=q->next;
	q->next=p;
	p->next=NULL;
	num++;
}

int Stack::Empty()
{
	return !num;
}

int Stack::Pop()
{
	int e;
	if(Empty())
	{
		cout<<"The Stack is empty!"<<endl;
		exit(0);
	}
	SNode *p,*q;
	p=Head;q=p;
	while(p->next)
	{
		q=p->next;
		if(!q->next)
			break;
		p=p->next;
	}
	p->next=NULL;
	e=q->data;
	delete q;
	num--;
	return e;
}

int Stack::GetTop()
{
	int e;
	if(Empty())
	{
		cout<<"The Stack is empty!"<<endl;
		exit(0);
	}
	SNode *p;
	p=Head;
	while(p->next)
	{
		p=p->next;
	}
	e=p->data;
	return e;
}

int GetSum(Stack &a)
{
	int sum=0,m,tmp;
	m=a.num;
	cout<<endl<<"Pop Stack List is:"<<endl;
	for(int i=0;i<m;i++)
	{
		tmp=a.Pop();
		cout<<"  "<<tmp;
		sum+=tmp;
	}
	cout<<endl;
	return sum;
}

void main()
{
	Stack s;
	int temp;
	srand((unsigned)time(NULL));
	cout<<"Push List is:"<<endl;
	for(int i=1;i<=100;i++)
	{
		temp=rand()%1000;
		if(s.Empty()||temp > s.GetTop())
		{
			cout<<"  "<<temp;
			s.Push(temp);
		}
		if(s.GetTop()>=999)
			break;
	}
	cout<<endl<<"SUM is:"<<GetSum(s)<<endl;
}