单链表的建立

C语言结构体实现单链表建立

要点就是要掌握p指针和p_last指针（指向p节点的前结点）的关系，利用p指针存储新节点，然后p_last指针记录每次存储的链表尾结点，就好了：

#include <stdio.h>
#include <malloc.h>
struct Node *creat(int n);

//linked list create:
typedef struct Node
{
    int data;
    struct Node *next;
}node,*listptr;  //这样书写后 struct Node = node
                 //           struct Node * = listptr
                 //相当于定义了一个宏;

struct Node *creat(int n)
{
    int i;
    struct Node *head, *p1, *p1_last;
    int a;
    head = NULL;
    printf("input the integers:\n");
    for(i=0; i<n; i++)
    {
        p1 = (listptr)malloc(sizeof(node)); //storage allocation
        scanf("%d",&a);
        p1->data = a;
        if(head == NULL)
        {
            head = p1;
            p1_last = p1;
        }
        else
        {
            p1_last->next = p1;
            p1_last = p1;
        }
    }
    p1_last->next = NULL;
    return head;
};

int main()
{
    //linked list
    //list create practice:
{


    int n;
    printf("please input the count of the nodes you want to creat: ");
    scanf("%d",&n);

    listptr head;
    head = creat(n);
    printf("these elements are:\n");
    while(head)
    {
        printf("%d ->",head->data);
        head = head->next;
    }
    printf("Null");


}
    return 0;
}