数据结构与算法-实验2-自定义栈，并实现push、pop、改栈顶元素、取栈顶元素

#include <iostream>

using namespace std;

 

const int maxnum = 3;

typedef struct Datastack                //定义栈中层数据类型

{

int data;                                          //节点中数据类型

struct Datastack  * pre, *next;    //双向栈

}datastack;

 

datastack *Create_stack();                          //创建栈,返回计数节点指针

 

datastack *push_stack(datastack *p,
int data);       //进栈

 

datastack *pop_stack(datastack *p);                 //出栈

 

datastack *changeTop_stack(datastack *p,
int data);  //改栈顶元素

 

int top_stack(datastack *p);                        //取栈顶元素

 

bool Isempty_stack(datastack *p);                   //栈空判断

 

bool Isfull_stack(datastack *p);                    //栈满判断

 

 

 

int main()

{

datastack *head =
NULL;                       //定义头指针  

cout << "Create_stack() 正在创建一个栈区域... ";   //创建栈存储区

head = Create_stack();

if (head !=
NULL)

{

cout << "创建栈存储区成功！\n";

}

else

{

cout << "创建栈存储区失败！\n";

return 0;

}

 

cout << "Isempty() return ";   //判空

if (Isempty_stack(head))

{

cout << "现在栈为空！\n";

}

else

{

cout << "现栈中存在元素！\n";

}

cout << "push(2)" << endl;     //进栈第一个元素

head = push_stack(head, 2);

cout << "top() return " << top_stack(head) << endl;

 

cout << "push(5)" << endl;     //进栈第二个元素

head = push_stack(head, 5);

cout << "top() return " << top_stack(head) << endl;

 

cout << "push(11)" << endl;    //进栈第三个元素

head = push_stack(head, 11);

cout << "top() return " << top_stack(head) << endl;

 

cout << "changeTop_stack()=6;" << endl;    //改变栈顶元素

head = changeTop_stack(head, 6);

cout << "changeTop_stack() return " << top_stack(head) << endl;

 

cout << "Isfull(): return ";  //判满

if (Isfull_stack(head))

{

cout << "栈已满！\n";

}

else

{

cout << "栈中还可以存储元素！\n";

}

 

cout << "pop(6)" << endl;     //出栈第一个元素

head = pop_stack(head);

cout << "top() return " << top_stack(head) << endl;

 

cout << "pop(5)" << endl;     //出栈第二个元素

head = pop_stack(head);

cout << "top() return " << top_stack(head) << endl;

 

cout << "pop(2) return " << endl;     //出栈第三个元素

head = pop_stack(head);

cout << "Isempty() return ";   //判空

if (Isempty_stack(head))

{

cout << "现在栈为空！\n";

}

else

{

cout << "现栈中存在元素！\n";

}

free(head);

return 0;

}

 

datastack *Create_stack()         //创建一个栈计数节点，最后返回栈底指针

{

datastack *p =
NULL;

datastack *s =
NULL;

s = (datastack *)malloc(sizeof(datastack));     //只创建计数节点

s->pre = NULL;

s->data = 0;

s->next = NULL;

p = s;

return  p;

}

 

//进栈

datastack *push_stack(datastack *p,
int data)

{

datastack  *s =
NULL;

if (Isfull_stack(p))     //判满

{

cout << "栈已满，入栈操作失败！\n";

return p;

}

if (p->data == 0)

{

s = (datastack *)malloc(sizeof(datastack));  //节点空间

s->pre = p;

s->data = data;

s->next = NULL;

p->next = s;

p->data++;

}

else

{

s = (datastack *)malloc(sizeof(datastack));  //新节点空间

s->pre = p->next;

s->data = data;

s->next = NULL;

(p->next)->next = s;

p->next = s;

p->data++;

}

 

return p;

}

 

//出栈

datastack *pop_stack(datastack *p)

{

datastack *pfree =
NULL;

if (Isempty_stack(p))     //判空

{

cout << "栈已空，出栈操作失败！\n";

return p;

}

pfree = p->next;

p->next = pfree->pre;

(p->next)->next =
NULL;

pfree->pre = NULL;

free(pfree);

p->data--;

return p;

}

 

//取栈顶元素

int top_stack(datastack *p)

{

if (Isempty_stack(p))     //判空

{

cout << "栈已空，栈顶无元素！\n";

return 0;

}

return (p->next)->data;

}

 

//改栈顶元素

datastack *changeTop_stack(datastack *p,
int data)

{

if (Isempty_stack(p))     //判空

{

cout << "栈已空，改栈顶元素操作失败！\n";

return p;

}

(p->next)->data =
data;

return p;

}

//判栈满

bool Isfull_stack(datastack *p)

{

if (p->data == maxnum)

{

return true;

}

return false;

}

 

//判栈空

bool Isempty_stack(datastack *p)

{

if (p->data == 0)

{

return true;

}

return false;

}