C语言实现 栈 的链式存储

前篇文章已分析栈的顺序存储，以下分析栈的链式存储。并采取不同于上文的构建方式，实现入栈（push）、出栈（pop）、返回栈顶(peek)等操作。

1 结构体构建链表节点

typedef struct Node //链表节点构造
{
    void *data;        //数据域，传址，任意数据类型
    struct Node *next; //指针域
} Node;

2 结构体构建栈

typedef struct Stack //栈
{
    Node firstNode; //栈存储的首个链表节点
    int size;       //栈的大小
} Stack;

3 栈的初始化

Stack *initStack() //栈的初始化
{
    Stack *stack = (Stack *)malloc(sizeof(stack)); //向堆区申请内存
    if (stack == NULL)
        return NULL;              //内存申请失败返回NULL
    stack->firstNode.next = NULL; //初始化
    stack->firstNode.data = NULL;
    stack->size = 0;
    return stack;
}

4 节点入栈

int push(Stack *stack, void *data) //入栈，本质为头插插入节点
{
    if (stack == NULL || data == NULL)
        return 0;
    Node *node = (Node *)malloc(sizeof(Node));
    node->data = data;
    node->next = NULL;
    node->next = stack->firstNode.next; //有效首节点为firstNode.next
    stack->firstNode.next = node;
    stack->size++;
    return 1;
}

5 出栈

void *pop(Stack *stack) //出栈，本质为删除首个有效节点
{
    if (stack == NULL)
        return NULL;
    Node *popNode = stack->firstNode.next;//出栈节点
    stack->firstNode.next = stack->firstNode.next->next;
    stack->size--;
    return popNode;
}

6 返回栈顶元素

void *peek(Stack *stack) //返回栈顶数据,单未删除
{
    if (stack == NULL || stack->size == 0)
        return NULL;
    return stack->firstNode.next;
}

7 空栈判断

int isEmptyStack(Stack *stack) //判断是否栈空
{
    if (stack == NULL)
        return -1;
    return stack->size == 0;
}

8 栈大小

int sizeOfStack(Stack *stack)//判断栈大小
{
    if (stack == NULL)
        return -1;
    return stack->size;
}

9 释放栈

void destroyStack(Stack *stack)//释放栈
{
    if (stack == NULL)
        return;
    free(stack);
    stack = NULL;
}

10 测试与运行

#include <stdio.h>
#include <stdlib.h>
typedef struct Student//测试数据类型
{
    int id;
    char name[20];
} Student;
int main()
{
    Student stuArray[] = {{1, "jakes1"}, {2, "jakes2"}, {3, "jakes3"}, {4, "jakes4"}, {5, "jakes5"}};
    Stack *stack = initStack();
    for (int i = 0; i < sizeof(stuArray) / sizeof(stuArray[0]); i++)
    {
        push(stack, &stuArray[i]);//Student数组依次入栈
        Node *peekNode = (Node *)peek(stack);//peek栈顶
        Student *stu = (Student *)peekNode->data;
        printf("栈顶->id:%d name:%s\t  栈大小->size:%d\t 栈空(1为空)->%d\t\n", stu->id, stu->name, sizeOfStack(stack), isEmptyStack(stack));
    }
    while (!isEmptyStack(stack))
    {
        Node* popNode = pop(stack);
        free(popNode);
        popNode = NULL;
        printf("栈大小->size:%d\t   栈空(1为空)->%d\t\n", sizeOfStack(stack), isEmptyStack(stack));
    }
    return 0;
}

运行结果如下：