#include<stdio.h>
void shuru(int num1);
void look(int num1);
void modify(int num1);
void tuichu(int num1);
 struct grade                   /* 成绩结构声明     */
   {  char name[20];
      int math;                   /* 数学成绩         */
      int english;                /* 英语成绩         */
      int computer;               /* 电脑成绩         */
   };
   typedef struct grade node;
    node student[9];

void main()
{
   int i;
   int num1;
   int num;                       /* 学生人数         */
   int select;
  printf("***************************************************\n");
  printf("*                                                 *\n");  
  printf("*            欢迎进入学生成绩管理系统             *\n");
  printf("*                                                 *\n");
  printf("***************************************************\n");
  printf("请先录入学生个人成绩及信息，请输入学生人数.(小于9) ==> ");
  scanf("%d",&num);  /* 读取学生人数     */
  shuru(num);
}
void shuru(int num1)
{
    int j=0;
    int select;
    int grade1,grade2,grade3;
    while(j<num1)
    {
      printf("学生编号: %d\n",j + 1);
      printf("请输入学生姓名. ==> ");
      scanf("%s",&student[j].name[j]);  
      printf("请输入数学成绩. ==> ");
      scanf("%d",&student[j].math);            
      printf("请输入英语成绩. ==> ");
      scanf("%d",&student[j].english);      
      printf("请输入计算机成绩. ==> ");
      scanf("%d",&student[j].computer);   
      ++j;   
    }
void look(int num1)
{
    int j=0;
    int select;
    int grade1,grade2,grade3;
}
void modify(int num1)
{
    int j=0;
    int select;
    int grade1,grade2,grade3;
}
void tuichu(int num1)
{
    int j=0;
    int select;
    int grade1,grade2,grade3;
}   
    while(1)
   {
      printf("*****************************************************\n");
      printf("*               操   作  选   项                    *\n");      
      printf("*               1: 查  询  成  绩                   *\n");
      printf("*               2: 修  改  成  绩                   *\n");
      printf("*               3: 退  出  操  作                   *\n");
      printf("*****************************************************\n");
      printf("请输入选项( 1 到 3 ). ==> ");
      scanf("%d",&select);
      if ( select != 3 )
      {
         printf("请输入学生学号( 1到 9). ==> ");
         scanf("%d",&num1);
      }
      switch(select)
      {
         case 1:
               grade1=student[num1-1].math;
               grade2=student[num1-1].english;
               grade3=student[num1-1].computer;
               printf("查询到学号为:%d的成绩是:math: %d english: %d computer %d\n",num1,grade1,grade2,grade3);
               look(num1);
               break;                  
         case 2:                  
               grade1=student[num1-1].math;
                grade2=student[num1-1].english;
               grade3=student[num1-1].computer;
               printf("查询到学号为:%d的成绩是:math: %d english: %d computer %d\n",num1,grade1,grade2,grade3);
               printf("请输入新成绩.==>");
               scanf("%d %d %d",&grade1,&grade2,&grade3);
               student[num1-1].math=grade1;
               student[num1-1].english=grade2;
               student[num1-1].computer=grade3;
               break;   
         case 3:
               exit(1);
               break;
      }
}
}

求大神帮忙啊？？

我不懂怎么调用它啊，你能告诉我方法吗？

求大神啊。。。。

如何让这后面的三个函数调用，可否帮我解决？谢谢了哇！

的确，你猜对了，我现在就不知如何定义look，modify，tuichu这三个函数，就是这三个函数里面该写入什么？求指教。。。。。