链表的构建

1.链表的构建及其内容的输出：

Description

建立一个有若干个学生信息的单向链表，并对链表进行查询和输出。学生信息包括学号、姓名、一门课程成绩。

Input

从键盘输入若干学生信息，以学号输入0作为结束标记。其中，假设有效分数都在0~100之间。

Output

输出所有学生的信息。每个学生的信息占据一行。如果链表为空，则输出“LinkList is Null”，输出不包含双引号。

Sample Input

1011anney891012frank911013susan940

Sample Output

1011 anney 891012 frank 911013 susan 94

我写的c代码：

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#define N 21
typedef struct student
{
    long ID;
    char name[N];
    int score;
    struct student *next;
}STU;

STU *CreateList();
void PrintList(STU *head);
void FreeList(STU *head);

int main()
{
    STU *head;
    head = CreateList();
    PrintList(head);
    FreeList(head);
    return 0;
}

STU *CreateList()
{
    STU *head = NULL, *p, *q, *r;
    p = (STU *)malloc(sizeof(STU));
    head = p;
    if(head == NULL)
    {
        printf("LinkList is Null\n");
        exit(0);
    }
    q = p;
    r = head;
    scanf("%ld", &q->ID);
    while(q->ID != 0)
    {
        getchar();
        scanf("%s", q->name);
        scanf("%d", &q->score);
        p = (STU *)malloc(sizeof(STU));
        q->next = p;
        r = q;
        q = p;
        scanf("%ld", &q->ID);
    }
    r->next = NULL;
    return head;
}

void PrintList(STU *head)
{
    STU *p;
    p = head;
    if(p->ID == 0)
    {
        printf("LinkList is Null\n");
        exit(0);
    }
    while(p != NULL)
    {
        printf("%ld ", p->ID);
        printf("%s", p->name);
        printf(" %d\n", p->score);
        p = p->next;
    }
    return;
}

void FreeList(STU *head)
{
    STU *p = head, *q;
    while(p != NULL)
    {
        q = p -> next;
        free(p);
        p = q;
    }
    return;
}