栈的动态实现

栈的动态实现

• 栈是一种先进后出的数据结构，已经使用数组实现过栈，这里通过链表来实现栈；
• 对于栈来说，添加元素和删除元素都在一端进行，所以实现过程是比较容易的；
• 按照栈的数据结构要求首先需要实现一下几种操作：
  
  • 1.栈的初始化操作CreateStack()；
  • 2.添加元素操作push()；
  • 3.删除元素操作pop();
  • 4.访问栈顶元素top();
  • 5.栈的大小判断操作StackSize();
• 首先需要定义栈的数据类型

typedef struct StackNode *StackNodePointer;struct StackNode{    int data;    StackNodePointer next;};

• 这里仅仅模拟实现一个栈，所以对于第一个节点的指针变量使用全局变量的方式，首先进行栈的初始化工作；

StackNodePointer snode = NULL;StackNodePointer CreateStack(){    snode = (StackNodePointer)malloc(sizeof(StackNodePointer));    snode->data = 0;    snode->next = NULL;    return snode;}

• 栈里面添加元素，就是链表元素的插入操作，可以使用头插法，也可以使用尾插法，这里是用头插法；

void push(int value){    StackNodePointer newhead = NULL;    newhead = (StackNodePointer)malloc(sizeof(StackNodePointer));    newhead->data = value;    newhead->next = snode;    snode = newhead;}

• 栈里面删除元素其实就是链表头节点的删除操作(因为元素插入使用的是头插法)；

void pop(){    if(snode->next==NULL){        fprintf(stderr,"The stack is NULL\n");        exit(EXIT_FAILURE);    }    StackNodePointer previous = snode;    snode = snode->next;    free(previous);}

• 访问栈顶元素，不进行元素的删除操作，所以需要由返回值类型一般来说需要是定义的栈的数据类型；

StackNodePointer top(){    if(snode->next==NULL){        fprintf(stderr,"The Stack is NULL\n");        exit(EXIT_FAILURE);    }    return snode;}

• 栈的大小统计函数；

int StackSize(){    int size = 0;    while (snode->next != NULL)    {        snode = snode->next;        ++size;    }    return size;}

• 栈的打印函数，这个主要是用来判断里面元素的存储情况的；

void PrintStack(){    StackNodePointer PrintNode = snode;    while (PrintNode->next != NULL)    {        printf("[ %d ]\n", PrintNode->data);        PrintNode=PrintNode->next;    }}

• 程序运行的完整程序；

#include<stdio.h>#include<stdlib.h>typedef struct StackNode *StackNodePointer;struct StackNode{    int data;    StackNodePointer next;};StackNodePointer snode = NULL;StackNodePointer CreateStack(){    snode = (StackNodePointer)malloc(sizeof(StackNodePointer));    snode->data = 0;    snode->next = NULL;    return snode;}void push(int value){    StackNodePointer newhead = NULL;    newhead = (StackNodePointer)malloc(sizeof(StackNodePointer));    newhead->data = value;    newhead->next = snode;    snode = newhead;}void pop(){    if(snode->next==NULL){        fprintf(stderr,"The stack is NULL\n");        exit(EXIT_FAILURE);    }    StackNodePointer previous = snode;    snode = snode->next;    free(previous);}StackNodePointer top(){    if(snode->next==NULL){        fprintf(stderr,"The Stack is NULL\n");        exit(EXIT_FAILURE);    }    return snode;}int StackSize(){    int size = 0;    while (snode->next != NULL)    {        snode = snode->next;        ++size;    }    return size;}void PrintStack(){    StackNodePointer PrintNode = snode;    while (PrintNode->next != NULL)    {        printf("[ %d ]\n", PrintNode->data);        PrintNode=PrintNode->next;    }}int main(){    CreateStack();    push(10);    push(9);    push(8);    push(7);    push(6);    push(5);    push(4);    push(3);    push(2);    push(1);    PrintStack();    pop();    printf("The top is [%d]\n",top()->data);    PrintStack();    printf("size: [ %d ]\n", StackSize());    return 0;}