链表的基本操作yc

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

typedef struct test{
    int dat;
    struct test *next;
}node;

node *create_node()
{
    node *p,*s,*head;
    int d,cycle=1;

    head = (node *)malloc(sizeof(node));
    p = head;
    printf("Please input your link_list data:\n");
    while(cycle) {
        scanf("%d",&d);
        if(d!=0) {
            s = (node *)malloc(sizeof(node));
            s->dat = d;
            p->next = s;
            p = s;
        }

        else cycle = 0;
    }

    head = head->next;
    p->next = NULL;

    return (head);
}

int list_len(node *head)
{
    int n = 0;
    node *p;
    p = head;
    while(p!=NULL) {
        p = p->next;
        n++;
    }

    return n;
}

void print_list(node *head)
{
    node *p;

    p = head;
    if(p!=NULL) {
        while(p!=NULL) {
            printf("%d\t",p->dat);
            p = p->next;
        }
    }
}


int main(void)
{
    node *t;
    int len;

    t=create_node();
    len = list_len(t);
    printf("len=%d\n",len);
    print_list(t);
    return 0;

}