藍色代表憂鬱 那我代表什麼

功能需求:

新增一個更新的功能在選項5,此功能可由使用者輸入欲更新的學號資料，如果串列裡有此學號，則要求使用者輸入新的學號，

姓名，分數，並將新的學號，姓名，分數印出來，若沒有則提示使用者串列裡沒有此筆資料

*提示:可以用strcmp來進行字串的比較，如果相等的話會回傳0，如strcmp(id1,id2)

-----------------從下面開始---------------

#include <stdio.h>
#include <stdlib.h>
struct student{
       char id[10];
       char name[10];
       int score;
       struct student *next;
};
struct student *insert_f(struct student *);
struct student *delete_f(struct student *);
void show_f(struct student *);
struct student *update_f(struct student *);
int main(int argc, char *argv[])
{
  struct student *head=NULL;
  char option;
  do{
   printf("<<<<Main function>>>>>>>>>\n");
   printf("====<1> insert============\n");
      printf("====<2> delete============\n");
      printf("====<3> show==============\n");
      printf("====<4> quit==============\n");
      printf("====<5> update============\n");
      printf("請輸入您的選擇:");
      option=getche();
      printf("\n");
      switch(option)
      {
          case '1':
               head=insert_f(head);
               break;
          case '2':
               head=delete_f(head);
               break;
          case '3':
               show_f(head);
               break;
          case '4':
               printf("Bye Bye\n");
               break;
          case '5':
               head=update_f(head);
               break;    
          default:
               printf("Wrong option\n");
      }
      }while(option !='4');
      system("PAUSE"); 
      return 0;
}

struct student *update_f(struct student *head) {
       struct student *find_node;
       struct student *ptr;
       int checkPoint=0;
       char enter[10];

       if(head==NULL || enter==NULL)
    {
          system("CLS");
    printf("沒有學生資料存在!!\n\n");
          return NULL;
       }
       system("CLS");
       printf("<<<<update function>>>>\n");
       printf("請輸入欲更新的學生的學號:");
       scanf("%s",enter);
       if(head==NULL || enter==NULL)
    {
          system("CLS");
    printf("沒有學生資料存在!!\n\n");
          return NULL;
       }

       ptr=head;
    while(ptr!=NULL)
    {
          if(strcmp(ptr->id,enter)==0)
    {
             find_node=ptr;
             checkPoint=1;
          }
          ptr=ptr->next;
       }
      
       if(checkPoint==0)
    {
          system("CLS");
    printf("查無此學號資料!!\n\n");
       }
    else
    {
          system("CLS");
    printf("請輸入新的學生的學號:");
          scanf("%s",find_node->id);
          printf("請輸入新的學生的姓名:");
          scanf("%s",find_node->name);
          printf("請輸入新的學生的分數:");
          scanf("%d",&find_node->score);
          printf("資料已更新\n");
          printf("====================================\n");
          printf("==  %-10s  %-10s  %4s  ==\n","學號","姓名","分數");
          printf("====================================\n");
          printf("==  %-10s  %-10s  %4d  ==\n", find_node->id,find_node->name,find_node->score);
          printf("====================================\n");
       }       
       return head;              
}

struct student *insert_f(struct student *head)
{
       struct student *new_node;
       struct student *ptr;
       system("CLS");
       printf("<<<<Insert function>>>>\n");
       new_node=(struct student *)malloc(sizeof (struct student));
       printf("請輸入學生的學號:");
       scanf("%s",new_node->id);
       ptr=head;
    while(ptr!=NULL)
    {
          if(strcmp(ptr->id,new_node->id)==0)
    {
    system("CLS");
    printf("輸入的學號重覆!!\n");
    new_node=NULL;
    return head;
          }
          ptr=ptr->next;
       }
       printf("請輸入學生的姓名:");
       scanf("%s",new_node->name);
       printf("請輸入學生的分數:");
       scanf("%d",&new_node->score);
       new_node->next=head;
       head=new_node;
       printf("已插入資料\n\n");
       return head;
}
struct student *delete_f(struct student *head)
{
       struct student *del_node;
       system("CLS");
       printf("<<<<Delete function>>>>\n");
       if(head==NULL)
       {
           system("CLS");
     printf("沒有資料\n\n");
           return NULL;
       }
       del_node=head;
       head=head->next;
       printf("學生學號%s 已刪除!\n",del_node->id);
       free(del_node);
       return head;
}
void show_f(struct student *head)
{
     struct student *ptr;
     system("CLS");
     printf("<<<<Show function>>>>\n");
     if(head==NULL)
     {
        system("CLS");
  printf("沒有學生資料存在!!\n\n");
        return;
     }
     ptr=head;
     system("CLS");
     printf("====================================\n");
     printf("==  %-10s  %-10s  %4s  ==\n","學號","姓名","分數");
     printf("====================================\n");
     while(ptr!=NULL)
     {
         printf("==  %-10s  %-10s  %4d  ==\n",
         ptr->id,ptr->name,ptr->score);
         ptr=ptr->next;
     }
     printf("====================================\n");
}

-----------------從上面結束---------------