c - 如何理解链表结构中的指针 'next'？

Question

struct Node
{
   int a;
   struct Node *next;
};

next 将如何动态地指向？我读到 malloc 返回地址值 - 是这样吗？请解释struct Node *next。这是在结构中声明指针的默认方式吗？

Answer 1

如果您有此声明

struct Node
{
   int a;
   struct Node *next;
};

然后你可以像这样定义它:

struct Node node = {1, 0};

或

struct Node *node = (Node*) malloc(sizeof(struct Node)); 

<小时/>

当您想要将节点附加到 next 成员时，您可以像这样:

node.next = (Node*) malloc(sizeof(struct Node));

或

node->next = (Node*) malloc(sizeof(struct Node));

<小时/>

实验示例:

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

int main(int argc, char **argv) {
    struct Node
    {
       int a;
       struct Node *next;
    };

    struct Node node1;
    struct Node *node2 = (Node*) malloc(sizeof(struct Node)); 

    node1.a = 1;
    node2->a = 2;
    node1.next = node2;
    node2->next = (Node*) malloc(sizeof(struct Node));
    node2->next->a = 3;

    printf("node1.a = %d, node1->next->a node2->a = %d, node2->next->a = %d\n", node1.a, node2->a, node2->next->a);
}