用c实现带指针的堆栈

#include <stdio.h>
#include <stdlib.h>

// 定义堆栈节点结构
typedef struct StackNode {
    int data;
    struct StackNode* next;
} StackNode;

// 创建一个空的堆栈
StackNode* createStack() {
    return NULL;
}

// 判断堆栈是否为空
int isEmpty(StackNode* root) {
    return (root == NULL);
}

// 入栈操作
void push(StackNode** root, int data) {
    StackNode* newNode = (StackNode*)malloc(sizeof(StackNode));
    if (newNode == NULL) {
        printf("内存分配失败\n");
        return;
    }
    newNode->data = data;
    newNode->next = *root;
    *root = newNode;
    printf("%d 入栈成功\n", data);
}

// 出栈操作
int pop(StackNode** root) {
    if (isEmpty(*root)) {
        printf("堆栈为空\n");
        return -1;
    }
    StackNode* temp = *root;
    *root = (*root)->next;
    int popped = temp->data;
    free(temp);
    return popped;
}

// 获取栈顶元素
int peek(StackNode* root) {
    if (isEmpty(root)) {
        printf("堆栈为空\n");
        return -1;
    }
    return root->data;
}

// 打印堆栈中的元素
void printStack(StackNode* root) {
    if (isEmpty(root)) {
        printf("堆栈为空\n");
        return;
    }
    printf("堆栈中的元素：\n");
    while (root != NULL) {
        printf("%d\n", root->data);
        root = root->next;
    }
}

int main() {
    StackNode* stack = createStack();

    push(&stack, 10);
    push(&stack, 20);
    push(&stack, 30);

    printf("栈顶元素：%d\n", peek(stack));

    printf("出栈：%d\n", pop(&stack));
    printf("出栈：%d\n", pop(&stack));

    printStack(stack);

    return 0;
}