1数据结构——链式栈c代码实现

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

typedef int ElemType;
typedef struct Node {
    ElemType data;
    struct Node *next;
} LinkStack;

void InitStack(LinkStack **s) {
    *s = (LinkStack *)malloc(sizeof(LinkStack));
    (*s)->next = NULL;
}

int StackEmpty(LinkStack *s) {
    return s->next == NULL;
}

void Push(LinkStack *s, ElemType e) {
    LinkStack *p = (LinkStack *)malloc(sizeof(LinkStack));
    p->data = e;
    p->next = s->next;
    s->next = p;
}

int Pop(LinkStack *s, ElemType *e) {
    if (StackEmpty(s)) {
        return 0;
    }
    LinkStack *p = s->next;
    *e = p->data;
    s->next = p->next;
    free(p);
    return 1;
}

int GetTop(LinkStack *s, ElemType *e) {
    if (StackEmpty(s)) {
        return 0;
    }
    *e = s->next->data;
    return 1;
}

void DestroyStack(LinkStack **s) {
    while ((*s)->next != NULL) {
        LinkStack *p = (*s)->next;
        (*s)->next = p->next;
        free(p);
    }
    free(*s);
    *s = NULL;
}

int main() {
    LinkStack *s;
    InitStack(&s);
    Push(s, 1);
    Push(s, 2);
    Push(s, 3);
    ElemType e;
    Pop(s, &e);
    printf("%d\n", e);
    GetTop(s, &e);
    printf("%d\n", e);
    DestroyStack(&s);
    return 0;
}