#include<stdio.h>
#include<stdlib.h>
#include <string.h>
#include <malloc.h>
struct Student
{
 int num;//學號
 char name[20];//名字
 char sex[2];
 int age;
 struct Student *next;
};
void insert(struct Student **head); //插入
void print(struct Student *head); //遍歷所有鏈表
void dele(struct Student **head); //刪除 指定內容
void modify(struct Student **head); // 修改內容
void find(struct Student *head); //查找學生信息
int modify_menu();
int main()
{
 struct Student *head = NULL;
 int x;
 do
 {
 printf("------------------------------------------\n");
 printf("    學生管理系統(tǒng)     \n"); 
 printf("           \n");
 printf(" 1 增加學生   2 刪除學生  \n");
 printf("           \n");
 printf(" 3 修改資料   4 查找學生  \n"); 
 printf("           \n"); 
 printf(" 5 顯示所有學生  0 退出系統(tǒng)  \n");
 printf("           \n");
 printf("------------------------------------------\n");
 printf("請輸入你需要使用的功能\n");
 scanf("%d",&x);
 switch(x)
 {
 case 0 : break;
 case 1 :
 insert(&head);
 break;
 case 2 :
 dele(&head);
 break;
 case 3 :
 modify(&head);
 break;
 case 4 :
 find(head);
 break;
 case 5 :
 print(head);
 break;
 default :
  printf ("選擇錯誤！??！\n");
  break;
 }
 }while(x);
}
void insert(struct Student **head)
{
 
 struct Student *p = (struct Student*)malloc(sizeof(struct Student));
 struct Student *stu=NULL;
 printf("num:");
 scanf("%d",&(p->num));
 printf("name:");
 scanf("%s",(p->name));
 printf("sex:");
 scanf("%s",p->sex);
 printf("age:");
 scanf("%d",&p->age);
 p->next=NULL;
 if(*head == NULL)
 {
  *head = p;
 }
 else
 {
  stu = *head;
  while(stu->next != NULL)
  {
   stu = stu->next;
  }
  stu->next = p;
 }
}
void print(struct Student *head)
{
 printf("學號  名字  性別 年齡 \n");
 while(head != NULL)
 {
 printf("%5d %10s  %s  %d\n",head->num,head->name,head->sex,head->age);
 head=head->next;
 }
}
void dele(struct Student **head)
{
 char arr1[20];
 struct Student *p1 = NULL;//指向要刪除的前一個結點
 struct Student *p2 = *head;//指向要刪除的結點
 printf("請輸入要刪除的學生\n");
 scanf("%s",arr1);
 while(p2 != NULL)
 {
 if(p1==NULL&&strcmp(arr1,p2->name)==0)
 {
 *head = p2->next;
 free(p2);
 break ;
 }
 else if(strcmp(arr1,p2->name)==0)
 {
 p1->next = p2->next;
 free(p2);
 break ; 
 }
 p1=p2;
 p2=p2->next;
 }
 print(*head);
 
}
void modify(struct Student **head) //修改 
{
 char arr[20];
 int x = 0;
 struct Student *p = *head;
 printf("請輸入需要修改資料的名字\n");
 scanf("%s",arr);
 while(p!=NULL)
 {
 if(strcmp(arr,p->name) ==0)
 {
 printf("請選擇修改的內容\n");
 x = modify_menu();
 printf("請輸入新的內容\n");
 switch(x)
 {
 case 1 :
 scanf("%d",&p->num);
 break;
 case 2 :
 scanf("%s",p->name);
 break;
 case 3 :
 scanf("%s",p->sex);
 break;
 case 4:
 scanf("%d",&p->age);
 break;
 default :
  printf ("選擇錯誤?。?！\n");
  break;
 }
 print(*head);
 break ;
 } 
 p=p->next;
 }
}
int modify_menu() //修改的菜單 
{
 int choose = 0;
 printf ("-----------------------------------\n");
 printf ("* 1 學號  2 姓名  *\n");
 printf ("* 3 性別  4 年齡  *\n");
 printf ("* 0 取消修改     *\n");
 printf ("-----------------------------------\n");
 scanf ("%d", &choose);
 return choose;
}
void find(struct Student *head)
{
 char arr[20];
 printf("請輸入學生姓名\n");
 scanf("%s",arr);
 while(head!=NULL)
 {
 if(strcmp(arr,head->name)==0)
 {
 printf("學號  名字  性別 年齡 \n");
 printf("%5d %10s  %s  %d\n",head->num,head->name,head->sex,head->age);
 }
 head=head->next;
 }
}