C语言使用链表实现学生信息管理系统

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define Max_Student_Num 10
#define Max_Str_len 20

typedef struct T_student{
 int number;
 char name [Max_Student_Num];
 char phone[Max_Student_Num];
};

typedef struct T_Node{
 struct T_student s;
 struct T_Node * next;
};

char command_str[]={"\n1 display all member;\n2 insert member;\n3 del member;\n4 exit\nCommand selection:"};

struct T_student students[Max_Student_Num];
struct T_Node * head = NULL;

int main(int argc, char* argv[])
{
 int command, i;
 struct T_student student;
 struct T_Node * pStu =head;
 memset(&student,0,sizeof(student));

 while(1){
  printf("%s",command_str);
  scanf("%d", &command);
  switch(command)
  {
  case 1:
   if(head==NULL){
    printf("empty!!!!!!!!!!!!\n");
    break;
   }
   if(head->next==head){
    display_student(head);
   }else{
    pStu=head->next;
    do
    {
     display_student(pStu);
     pStu=pStu->next;
    }while(pStu!= head->next);
//
   }

   break;
  case 2:
   printf("enter new student number:");
   scanf("%d", &student.number);
   printf("enter new student name:");
   scanf("%s", &student.name);
   if(strlen(student.name) > Max_Str_len)
   {
    printf("name is too long!!\n");
    continue;
   }

   printf("enter new student phone:");
   scanf("%s", &student.phone);

   if(strlen(student.phone) > Max_Str_len)
   {
    printf("phone is too long!!\n");
    continue;
   }

   printf("\n");

   if(student.number != 0)
     insert_student(student);

   break;
  case 3:
   printf("Inter deleted student number:");
   scanf("%d", &student.number);
   del_student(student);
   break;
  case 4:
   return 0;
  default:
   printf("error command, try again\n");
   break;
  }
 }
}


void display_student( struct T_Node * pStu){
 printf("number:%d name:%s phone:%s \n",pStu->s.number,pStu->s.name,pStu->s.phone);
}

void insert_student(struct T_student student){

 struct T_Node* pNode ;
 struct T_Node* pStu =NULL;
 int size = sizeof(struct T_Node);
 pStu=(struct T_Node *)malloc (size);
 if(pStu == NULL){
  return ;
 }
 memcpy(&pStu->s,&student,sizeof(student));

 if(head==NULL){

   pStu->next=head;
   head=pStu;
   head->next=head;
   return ;
 }
 pStu->next = head->next;
 head->next=pStu;


}

void del_student(struct T_student student){
 struct T_Node *pNode =NULL,*p=NULL;
 if(head->next==head && head->s.number==student.number){
  pNode=head;
  head=NULL;
  free(pNode);
  printf("success");
  return;
 }
 for(pNode=head->next;pNode != head;pNode=pNode->next){
  if( pNode->next->s.number == student.number){
   p=pNode->next->next;

   free(pNode->next);
   pNode->next=p;

   printf("Delete success!\n");
   return;
  }

 }
 printf("Not Found\n");
}