#C语言# #链表# #文件#

Question

通过读取该文件显示到屏幕上来检查stud.txt文件中的数据
读取文件的时候有问题，可以帮忙看一下吗？

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

struct student
{
    char num[10];
    char name[20];
    int sub1;
    int sub2;
    int sub3;
    int ave;
    struct student *next;
};
struct student *head = NULL;

struct student *creat();//创建节点
struct student *save(struct student *head);//保存链表数据到文件
struct student *read();//从文件读取链表
void display_all();//显示所有学生信息

struct student *creat()//创建节点
{
    struct student *p1,*p2;
    p1=p2=(struct student*)malloc(sizeof(struct student));
    printf("请输入学生学号 姓名 语文成绩 数学成绩 英语成绩\n");
    scanf("%s %s %d %d %d",p1->num,p1->name,&p1->sub1,&p1->sub2, &p1->sub3);
    p1->ave = (p1->sub1+p1->sub2+p1->sub3)/3;
    fflush(stdin);
    head=p1;
    for(int i=1;i<3;i++)
    {
        p1=(struct student*)malloc(sizeof(struct student));
        scanf("%s %s %d %d %d",p1->num,p1->name,&p1->sub1,&p1->sub2, &p1->sub3);
        p1->ave = (p1->sub1+p1->sub2+p1->sub3)/3;
        fflush(stdin);
        p2->next=p1;
        p2=p1;
    }
    p2->next=NULL;
    display_all();
    return head;
}
void display_all()//显示所有学生信息
{
    struct student *p;
    p=head;
    if(p == NULL)
        printf("无学生信息!\n");
    else{
        printf("\n学生学号 姓名 语文成绩 数学成绩 英语成绩 平均成绩：\n");
        while(p != NULL)
        {
            printf("%s\t%s\t%d\t%d\t%d\t%d\n\n",p->num,p->name,p->sub1,p->sub2,p->sub3,p->ave);
            p=p->next;
        }
    }
}

struct student *save(struct student *head)//保存链表数据到文件
{
    struct student *p;
    FILE *fp;
    p=head;
    if((fp = fopen("stud.txt","w")) == NULL)
        printf("文件无法打开!\n");
    else
        fp=fopen("stu.txt","w");
    while(p != NULL)
    {
        fprintf(fp,"%s\t%s\t%d \t%d\t%d\t%d\n",p->num,p->name,p->sub1,p->sub2,p->sub3,p->ave);
        p=p->next;
    }
    fclose(fp);
    printf("保存成功!\n");
    return head;
}

struct student *read()//从文件读取链表
{
    struct student *p1,*p2;
    FILE *fp;
    int flag = 1;
    fp=fopen("stud.txt","r");
    printf("学生学号 姓名 语文成绩 数学成绩 英语成绩 平均成绩：\n");
    while(!feof(fp))
    {
        if(flag == 1) ///读取头
        {
            p1=(struct student *)malloc(sizeof(struct student));
            head=p1;
            p2=p1;
            fscanf(fp,"%s %s %d %d %d %d\n",p1->num,p1->name,&p1->sub1,&p1->sub2,&p1->sub3,&p1->ave);
            printf("%s\t%s\t%d\t%d\t%d\t%d\n",p1->num,p1->name,p1->sub1,p1->sub2,p1->sub3,p1->ave);
            flag--;
        }
        else
        {
            p1=(struct student *)malloc(sizeof(struct student));
            fscanf(fp,"%s %s %d %d %d %d\n",p1->num,p1->name,&p1->sub1,&p1->sub2,&p1->sub3,&p1->ave);
            printf("%s\t%s\t%d\t%d\t%d\t%d\n",p1->num,p1->name,p1->sub1,p1->sub2,p1->sub3,p1->ave);
            p2->next=p1;
            p2=p1;
        }
    }
    p2->next = NULL;
    fclose(fp);
    return head;
}

int main()
{
creat();
save(head);
read();
}

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct student
{
    char num[10];
    char name[20];
    int sub1;
    int sub2;
    int sub3;
    int ave;
    struct student* next;
};
struct student* head = NULL;
struct student* creat();//创建节点
struct student* save(struct student* head);//保存链表数据到文件
struct student* read();//从文件读取链表
void display_all();//显示所有学生信息
struct student* creat()//创建节点
{
    struct student* p1, * p2;
    p1 = p2 = (struct student*)malloc(sizeof(struct student));
    printf("请输入学生学号 姓名 语文成绩 数学成绩 英语成绩\n");
    scanf("%s %s %d %d %d", p1->num, p1->name, &p1->sub1, &p1->sub2, &p1->sub3);
    p1->ave = (p1->sub1 + p1->sub2 + p1->sub3) / 3;
    fflush(stdin);
    head = p1;
    for (int i = 1; i < 3; i++)
    {
        p1 = (struct student*)malloc(sizeof(struct student));
        scanf("%s %s %d %d %d", p1->num, p1->name, &p1->sub1, &p1->sub2, &p1->sub3);
        p1->ave = (p1->sub1 + p1->sub2 + p1->sub3) / 3;
        fflush(stdin);
        p2->next = p1;
        p2 = p1;
    }
    p2->next = NULL;
    display_all();
    return head;
}
void display_all()//显示所有学生信息
{
    struct student* p;
    p = head;
    if (p == NULL)
        printf("无学生信息!\n");
    else {
        printf("\n学生学号 姓名 语文成绩 数学成绩 英语成绩 平均成绩：\n");
        while (p != NULL)
        {
            printf("%s\t%s\t%d\t%d\t%d\t%d\n\n", p->num, p->name, p->sub1, p->sub2, p->sub3, p->ave);
            p = p->next;
        }
    }
}
struct student* save(struct student* head)//保存链表数据到文件
{
    struct student* p;
    FILE* fp;
    p = head;
    if ((fp = fopen("stud.txt", "w")) == NULL)
        printf("文件无法打开!\n");
    else
        fp = fopen("stu.txt", "w");
    while (p != NULL)
    {
        fprintf(fp, "%s\t%s\t%d \t%d\t%d\t%d\n", p->num, p->name, p->sub1, p->sub2, p->sub3, p->ave);
        p = p->next;
    }
    fclose(fp);
    printf("保存成功!\n");
    return head;
}
struct student* read()//从文件读取链表
{
    struct student* p1, * p2=new student;
    FILE* fp;
    int flag = 1;
    if ((fp = fopen("stud.txt", "r")) == NULL)
        printf("文件无法打开!\n");
    else
        fp = fopen("stu.txt", "r");
    printf("学生学号 姓名 语文成绩 数学成绩 英语成绩 平均成绩：\n");
    while (!feof(fp))
    {
        if (flag == 1) ///读取头
        {
            p1 = (struct student*)malloc(sizeof(struct student));
            head = p1;
            p2 = p1;
            fscanf(fp, "%s %s %d %d %d %d\n", p1->num, p1->name, &p1->sub1, &p1->sub2, &p1->sub3, &p1->ave);
            printf("%s\t%s\t%d\t%d\t%d\t%d\n", p1->num, p1->name, p1->sub1, p1->sub2, p1->sub3, p1->ave);
            flag--;
        }
        else
        {
            p1 = (struct student*)malloc(sizeof(struct student));
            fscanf(fp, "%s %s %d %d %d %d\n", p1->num, p1->name, &p1->sub1, &p1->sub2, &p1->sub3, &p1->ave);
            printf("%s\t%s\t%d\t%d\t%d\t%d\n", p1->num, p1->name, p1->sub1, p1->sub2, p1->sub3, p1->ave);
            p2->next = p1;
            p2 = p1;
        }
    }
    p2->next = NULL;
    fclose(fp);
    return head;
}
int main()
{
    creat();
    save(head);
    read();
}