c语言链表文件操作实现学生信息管理系统

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<time.h>
#include <unistd.h>
#include<windows.h>
struct student{
  int age;
  float math;
  struct student *pnext;
  char stu_name[20];
  int code;//学生学号 
};
void menu(){//操作界面 
  printf("    |________________________________________________|\n");  
    printf("    |                                                |\n");  
    printf("    |                学生信息管理系统                |\n");  
    printf("    |                                                |\n");  
    printf("    |               [0]退出系统                      |\n");  
    printf("    |               [1]增加学生信息                  |\n");  
    printf("    |               [2]删除学生信息                  |\n");  
    printf("    |               [3]修改学生信息                  |\n");  
    printf("    |               [4]查找学生的信息                |\n");  
    printf("    |               [5]按照学生成绩排序              |\n");  
    printf("    |               [6]浏览全部学生信息              |\n");  
    printf("    |               [7]保存学生信息到文件            |\n");  
    printf("    |               [8]按照学生学号排排序            |\n");  
    printf("    |               [9]打印链表信息                  |\n"); 
  printf("    |________________________________________________|\n"); 
}
void welcome(){
  system("color a0"); 
  printf("***********************************************\n");
  printf("\n");
  printf("\n");
  printf("\n");
  printf("*************欢迎进入学生信息管理系统**********");
  printf("\n");
  printf("\n");
  printf("\n");
  printf("************************************************\n");
} 
void free_link_list(struct student *phead){
  struct student *pre=phead;
  struct student *p=phead->pnext;
  while(p!=NULL){
    free(pre);
    pre=p;
    p=p->pnext;
  }
}
void save_student(student *phead)
{//保存学生信息到文件  
  FILE *fp=NULL;
  if(!(fp=fopen("student.txt","w"))){
    printf("打开文件失败 \n");
    exit(0); 
  }
  struct student *p=phead->pnext;
  while(p)
  { 
    fprintf(fp,"%d %s %d %f\n",p->code,p->stu_name,p->age,p->math);//写入文件 
    p=p->pnext;
  }
  fclose(fp);
  free_link_list(phead);
}
void add_student(student *phead)
{ 
  system("cls");
  menu(); 
  student *pnew=(student*)malloc(sizeof(student));
  pnew->pnext=phead->pnext;
  phead->pnext=pnew;
  printf("请输入学生的年龄:");
  scanf("%d",&pnew->age);
  printf("\n请输入学生的姓名:");
  scanf("%s",pnew->stu_name);
  printf("\n请输入学生的数学成绩：");
  scanf("%f",&pnew->math);
  printf("\n请您输入学生的学号:\n");
  scanf("%d",&pnew->code); 
  printf("\n添加成功！\n");
  sleep(1);
}
void del_student(student *phead){//删除学生信息 
  system("cls");
  menu();
  printf("\n请您输入该生的学号 ：\n");
  student *p=phead->pnext;
  int CODE;
  scanf("%d",&CODE);
  student *pre=phead;
  while(p!=NULL)
  { 
    if(p->code==CODE){
      pre->pnext=p->pnext;
      free(p);
      printf("\n**！！删除成功 ！！**\n"); 
      break;
    }
    else{
      p=p->pnext;
      pre=pre->pnext;
    } 
  }
}
void change_student(student *phead)
{//修改学生信息 
  student *p=phead->pnext;
  printf("请输入学生的学号：\n");
  int code;
  scanf("%d",&code);
  int i=0;
  while(p!=NULL)
  {
    if(p->code==code)
    { i=1;
      printf("\n*****找到该生*****\n");
      printf("学生学号\t   学生姓名\t  年龄 \t  高等数学\n");       
      printf("---------------------------------------------\n");
      printf("%d  \t   %s   \t    %d  \t  %f",p->code,p->stu_name,p->age,p->math);
      int a;
      printf("\n**请输入您的操作**\n");
      printf("---------------------------");
      printf("[1]修改学生数学成绩\n"); 
      scanf("%d",&a);
      printf("请输入修改的数学成绩为：\n");
      float Math;
      scanf("%f",&Math);
      switch(a)
      {
        case 1: p->math=Math;
        printf("修改成功！\n");
        printf("学生学号\t   学生姓名\t  年龄 \t  高等数学\n");       
        printf("---------------------------------------------\n");
        printf("%d  \t   %s   \t    %d  \t  %f",p->code,p->stu_name,p->age,p->math);
        break; 
        default:printf("\n**输入错误!请重新输入....**\n");break; 
       } 
    }
    p=p->pnext;
  }
  if(!i)printf("**未找到该生**");
} 
void print_linklist(student *phead){
  system("cls");
  menu();
  struct student *p=phead->pnext;
  if(phead->pnext==NULL){
    printf("当前链表还没任何学生\n"); 
  }
  while(p!=NULL){
    printf("学生姓名：%s\n",p->stu_name);
    p=p->pnext;
  }
  }
 struct student *seek_student(struct student *phead){//查找学生
   system("cls");
   menu();
   struct student *p=phead->pnext;
   printf("\n请输入学生学号：\n");
   int CODE;
   int index=1;
   scanf("%d",&CODE);
   while(p!=NULL){
    if(p->code==CODE){
      printf("**找到该学生**");
      printf("****************************************\n");
      printf("学号\t姓名\t年龄\t高等数学\n");
      printf("%d\t%s\t%d\t%.2f\n",p->code,p->stu_name,p->age,p->math); 
      index=0;
      break;
     }   
     p=p->pnext;
   }
   if(index){
   printf("\n**************未找到该学生***************\n");
   }  
}
 struct student *find_pos_score(struct student *phead,student *pend){
  float key=phead->math;
  struct student *p=phead;
  struct student *q=phead->pnext;
  float item=0;
  while(q!=pend){
    if(q->math>key){
      p=p->pnext;
      item=q->math;
      q->math=p->math;
      p->math=item;
      int CODE=q->code;
      q->code=p->code;
      p->code=CODE;
      char str[20];
      strcpy(str,q->stu_name);
      strcpy(q->stu_name,p->stu_name);
      strcpy(p->stu_name,str);
      int a=q->age;
      q->age=p->age;
      p->age=a;
    }
    q=q->pnext;
  }
  float temp=phead->math;
  phead->math=p->math;
  p->math=temp;
  int item2 =phead->code;
  phead->code=p->code;
  p->code=item2;
  int index=phead->age;
  phead->age=p->age;
  p->age=index;
  char str[20];
  strcpy(str,phead->stu_name);
  strcpy(phead->stu_name,p->stu_name);
  strcpy(p->stu_name,str);
  return p; 
}
void quick_sort_score(student *phead,student *pend){
  if(phead!=pend){  
  student *pnode=find_pos_score(phead,pend);
  quick_sort_score(phead,pnode);
  quick_sort_score(pnode->pnext,pend);
}
}
void rank_student_by_score(struct student *phead,student *pend)
{ 
  system("cls");
  menu();
  printf("****************************************\n");
  printf("学号\t姓名\t年龄\t高等数学\n");
  quick_sort_score(phead,pend);
  struct student *p=phead;
  while(p!=NULL){
    printf("%d\t%s\t%d\t%.2f\n",p->code,p->stu_name,p->age,p->math);
    p=p->pnext; 
  }
}
struct student *find_pos_code(student *phead,student *pend){
  float key=phead->code;
  struct student *p=phead;
  struct student *q=phead->pnext;
  while(q!=pend){
    if(q->code<key){
      p=p->pnext;
      int item=q->code;
      q->code=p->code;
      p->code=item; 
      int AGE=q->age;
      q->age=p->age;
      p->age=AGE;
      float MATH=q->math;
      q->math=p->math;
      p->math=MATH;
      char str[20];
      strcpy(str,q->stu_name);
      strcpy(q->stu_name,p->stu_name);
      strcpy(p->stu_name,str);
    }
    q=q->pnext;
  }
  int pig=phead->code;
  phead->code=p->code;
  p->code=pig;
  int AGE2=phead->age;
  phead->age=p->age;
  p->age=AGE2;
  float MATH2=phead->math;
  phead->math=p->math;
  p->math=MATH2;
  char str1[20];
  strcpy(str1,phead->stu_name);
  strcpy(phead->stu_name,p->stu_name);
  strcpy(p->stu_name,str1);
  return p;
}
void quick_sort_code(struct student *phead,struct student *pend){
  if(phead!=pend){
    struct student *pnode=find_pos_code(phead,pend);
    quick_sort_code(phead,pnode);
    quick_sort_code(pnode->pnext,pend); 
}
}
void rank_student_by_code(struct student *phead,student *pend){//快排  
      system("cls");
      menu();
      printf("****************************************\n");
      printf("学号\t姓名\t年龄\t高等数学\n");
      quick_sort_code(phead,pend);
      struct student *p=phead;
      while(p!=NULL){
      printf("%d\t%s\t%d\t%.2f\n",p->code,p->stu_name,p->age,p->math);
      p=p->pnext; 
}
}
void load_all_student(struct student *phead){//将文件信息读入链表 
  FILE *fp=fopen("student.txt","r+");
  char stu_name[20];
  if(fp==NULL){
    printf("不能打开文件\n"); 
  }
  struct student *p=phead->pnext; 
  int c;
  rewind(fp);
  fseek(fp, 0, 2);
  c = ftell(fp);
  rewind(fp);
  while((c-2) != ftell(fp)){
    struct student *pnew=(student*)malloc(sizeof(student));
    fscanf(fp,"%d %s %d %f",&pnew->code,stu_name,&pnew->age,&pnew->math);
    strcpy(pnew->stu_name,stu_name);
    pnew->pnext=phead->pnext;
    phead->pnext=pnew;
  }
  fclose(fp);
  printf("\n加载成功！\n");
}
void show(){
  system("cls");
    menu();
    printf("请输入数字编号————以完成功能\n");
    int number;
    struct student *phead=(student *)malloc(sizeof(student));
    phead->pnext=NULL;
  load_all_student(phead);
    while(1)
  { 
    printf("**请输入数字**"); 
          scanf("%d",&number); 
      switch(number)
    {
    case 0:
    save_student(phead);
    printf("**************谢谢使用再见！**");
    exit(0);
    break;
      case 1:add_student(phead);
      break;
      case 2:del_student(phead);
      break;
      case 3:change_student(phead);
      break;
      case 4:seek_student(phead);
      break;
      case 5:rank_student_by_score(phead->pnext,NULL);
      break;
    case 6:
    break;printf("\n功能尚未开发敬请期待\n");break; 
    case 7:save_student(phead);break;
    case 8:rank_student_by_code(phead->pnext,NULL);break; 
    case 9:print_linklist(phead);break; 
    default : printf("*输入有误，请重新输入*");
    break; 
    }
  }
}
int main()
{
  welcome();//欢迎 
  sleep(2);//延迟 
  show();//展示操作功能 
  return 0;
}