设计了一个学生成绩管理系统,退出程序之前写入txt文件之后,打开文件发现里面的数值非常大,求点拨
另外,求平均分该怎么写代码呢?用链表来

*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define LEN sizeof(struct student)
#define INPUT %d %d %s %d %d %d %d %d %d %d %d %d %d
#define SCANF &pC->num,&pC->Class,pC->name,&pC->finish[0],&pC->finish[1],&pC->finish[2],&pC->finish[3],&pC->finish[4],&pC->finish[5],&pC->finish[6],&pC->finish[7],&pC->finish[8],&pC->finish[9]
#define PRINT pC->num,pC->Class,pC->name,pC->finish[0],pC->finish[1],pC->finish[2],pC->finish[3],pC->finish[4],pC->finish[5],pC->finish[6],pC->finish[7],pC->finish[8],pC->finish[9]
struct student
{
    int num;
    int Class;
    char name[10];
    int finish[10];
    struct student * next;
};
   
struct student *insert(struct student *head,
                       struct student *pNode)
{
    // pPrev为前驱结点位置，pNext为后继结点位置
    struct student *pPrev,*pNext;
    pNext = head;
    if(head == NULL) {     //空链表
        head = pNode;      //插入到第一个位置
        pNode->next = NULL;
    }else{                 //非空链表                      
        /*
        查找插入位置。
        将pNode->num与pNext->num相比较，
        如果pNode->num ＞ pNext-> num ，
        则待插入的结点应插在pNext所指的结点之后的某个位置，
        此时将pNext后移，并使pPrev指向刚才pNext所指的结点.
        */
        while((pNext != NULL) &&
              (pNode->num > pNext->num))  {
            pPrev = pNext;   
            pNext = pNext->next;
        }
            
        if (pNext == NULL)  {   //未找到插入位置
            pPrev->next = pNode;//插入到链表最后位置
            pNode->next = NULL;
        }else{
            if(head == pNext)   //第一个位置
                head = pNode;
            else                //其他位置
                pPrev->next = pNode;    
          
            pNode->next = pNext;
        }
    }
    return head ;
}
struct student * add_score()
{
    struct student *head = NULL;
    struct student *pC,*pEnd;
    pC =pEnd =(struct student*) malloc(LEN);
    puts("请输入学号(输入0退出):");
    //scanf("INPUT",SCANF);
    scanf("%d",&pC->num);printf("%d",pC->num);
    if(pC->num==0)
    {return head;}
    else
    puts("\n请输入班级(如:1):");
    scanf("%d",&pC->Class);
    puts("\n请输入姓名:");
    scanf("%s",pC->name);
    puts("\n请输入十次成绩:");
    scanf("%d %d %d %d %d %d %d %d %d %d",&pC->finish[0],&pC->finish[1],&pC->finish[2],&pC->finish[3],&pC->finish[4],&pC->finish[5],&pC->finish[6],&pC->finish[7],&pC->finish[8],&pC->finish[9]);
    while(pC->num>0)
    {
        if(head==NULL)
        {
            head=pC;
        }
        else
        {
            pEnd->next = pC;
        }
        pEnd=pC;
   
        head = insert(head , pC);
   
        pC=(struct student*)malloc(LEN);
      
        puts("请输入学号(输入0退出):");
        scanf("%d",&pC->num);
        if(pC->num==0)
        {return head;}
        else
        puts("\n请输入班级(如:一班):");
          scanf("%d",&pC->Class);
        puts("\n请输入姓名:");
         scanf("%s",pC->name);
        puts("\n请输入十次成绩:");
         scanf("%d %d %d %d %d %d %d %d %d %d",&pC->finish[0],&pC->finish[1],&pC->finish[2],&pC->finish[3],&pC->finish[4],&pC->finish[5],&pC->finish[6],&pC->finish[7],&pC->finish[8],&pC->finish[9]);
    }
    pEnd->next=NULL;
    return head;
}
struct student *display_one(struct student *head, int num)
{
    struct student *pC = head;
    if(num==0)
    {return head;}
    else
    {
    if(pC==NULL)
    puts("数据不存在.");
    else if(pC != NULL && num != pC->num)
    {
        printf("%d %d %s %d %d %d %d %d %d %d %d %d %d \n",pC->num,pC->Class,pC->name,pC->finish[0],pC->finish[1],pC->finish[2],pC->finish[3],pC->finish[4],pC->finish[5],pC->finish[6],pC->finish[7],pC->finish[8],pC->finish[9]);
    }
    }
    return head;
}



struct student *display_class(struct student *head,int Class)
{
    struct student *pC = head;
    while(pC!=NULL && Class==pC->Class)
    {
        printf("%d %d %s %d %d %d %d %d %d %d %d %d %d\n",pC->num,pC->Class,pC->name,pC->finish[0],pC->finish[1],pC->finish[2],pC->finish[3],pC->finish[4],pC->finish[5],pC->finish[6],pC->finish[7],pC->finish[8],pC->finish[9]);
        pC=pC->next;
    }
    return head;
}
struct student *alter(struct student *head,int num)
{
    int i,score;
    struct student *pC=head;
  
    if(head==NULL)
    {
        printf("学号不存在.");
        return NULL;
    }
    while(pC!=NULL && num!=pC->num)
    {
        pC=pC->next;
    }
   printf("pC == %p\n", pC);
    while(i!=0)
    {
        printf("您想要更改第几次作业情况?(输入0退出)\n");
           scanf("%d",&i);
           if(i!=0)
           {
               printf("\n请输入分数:");
               scanf("%d",&pC->finish[i-1]);
           }
    }
    return head;
}
struct student *delete_one(struct student *head, int num)
{
    struct student *pC,*pP;
    pC = head;
    if (pC == NULL)
    { 
        printf("没有数据.\n");
        return NULL;
    }
      
    while (pC != NULL && num != pC->num)
    {
         pP = pC;
         pC = pC->next;
    }
  
    if(pC!=NULL)
    {
        printf("删除学号:%d\n", num);
      
        if  (pC == head)
        {
            head = pC->next;                
        }
        else
        {               
            pP->next = pC->next;
        }
       // free(pC); 
    }
    else{
        printf("学号 %d 不存在!\n",num);
    }
  
    return head;      
}
//struct student *
void fileread(struct student *head)
{
    FILE *fp;
    struct student *pC=head;
    if((fp=fopen("record.txt","r+"))==NULL)
    {
        printf("文件打开错误!");
    }
    while(pC!=NULL)
    {
        fscanf(fp,"%d %d %s %d %d %d %d %d %d %d %d %d %d\n",&pC->num,&pC->Class,pC->name,&pC->finish[0],&pC->finish[1],&pC->finish[2],&pC->finish[3],&pC->finish[4],&pC->finish[5],&pC->finish[6],&pC->finish[7],&pC->finish[8],&pC->finish[9]);
        pC=pC->next;
    }
    fclose(fp);
}

void filesave(struct student *head)
{
    FILE *fp;
    struct student *pC=head;

    if((fp=fopen("record.txt","r+"))==NULL)
    {
        printf("文件打开错误!");
    }

    while(pC!=NULL)
    {
        fprintf(fp,"%d %d %s %d %d %d %d %d %d %d %d %d %d\n",pC->num,pC->Class,pC->name,pC->finish[0],pC->finish[1],pC->finish[2],pC->finish[3],pC->finish[4],pC->finish[5],pC->finish[6],pC->finish[7],pC->finish[8],pC->finish[9]);
        pC=pC->next;
    }
    fclose(fp);
}

int main()
{
    struct student *mHead,*pC;
    int num;
    int choice,Class;
    pC=mHead;

    fileread(mHead);

    while (choice!=7)
    {
        printf("\t\t\t欢迎进入学生作业完成情况管理系统\n");
        printf("\t\t\t--------------------------------\n\n\n");
        printf("1.录入某位学生某次作业的分数\n");
        printf("2.给定学号，显示某位学生的作业完成情况\n");
        printf("3.给定某个班级的班号，显示该班所有学生的作业完成情况\n");
        printf("4.给定某位学生的学号，修改该学生的作业完成信息\n");
        printf("5.给定某位学生的学号，删除该学生的信息\n");
        printf("6.提供一些统计各类信息的功能\n");
        printf("7.退出\n\n");
        printf("请选择功能:");

    scanf("%d",&choice);

    switch (choice)
    {
    case 1:
    add_score();break;

    case 2:
    printf("请输入学号:");
    scanf("%d",&num);
    display_one(mHead,num);break;

    case 3:
    printf("请输入班级:");
    scanf("%d",&Class);
    display_class(mHead,Class);break;

    case 4:
    printf("请输入学号:");
    scanf("%d",&num);
    alter(mHead,num);break;

    case 5:
    printf("请输入学号:");
    scanf("%d",&num);
    delete_one(mHead,num);break;

    case 6:

    case 7:
    ;}
    }
    filesave(mHead);

    return 0;
}

做

。

完完全全的c语言风格，你放错地方了。

错误不在于文件读取。

struct student *mHead,*pC;
    int num;
    int choice,Class;
    pC=mHead;

    fileread(mHead);

你看看你调用fileread的地方，传进去的head是没有初始化的，只是一片未知的内存的地址；
你读取文件的数量是不可控的（你根本不可能知道head的Next是不是为空）。

正确的保存方法是，先在第一行保存数量，
读取的时候，要一个节点一个节点的malloc出来，然后插入到链表中。

不用再详细了吧？

第一行添加数量是什么意思 求解释

数据应该是这样的：
如果你录入的学生数量是10个，则在record.txt的第一行写一个10；
读文件时，先int count;fscanf("%d",&count);
然后，for(i=0;i<count;i++){
struct student * pst = (struct student *)malloc(LEN);
【read(&st);】//读取一行数据
【添加到链表中】
}
你原来的代码中，链表都没创建，怎么从文件中读取？

[ 本帖最后由 CrystalFan 于 2011-12-16 22:21 编辑 ]