求大神看看异常怎么解决。

Question

#include<iostream>#include<fstream>#include<string>#include<stdio.h>#include<stdlib.h>#include<conio.h>//#include<iomanip>using namespace std;#define OK 1#define ERROR 0#define OVERFLOW -2#define LEN(a) sizeof(a)/sizeof(a[0]) typedef int Status; //Status 是函数返回值类型，其值是函数结果状态代码。typedef  int  ElemType; //ElemType 为可定义的数据类型，此设为int类型#define MAXSIZE 100//顺序表可能达到的最大长度//学生信息的定义：typedef struct {    char no[8];   //8位学号    char name[80]; //姓名 int age;//年龄 int sex; //性别    ElemType  price[4];     //成绩}Student;//顺序表的定义（第一个程序用）typedef  struct {  Student  *elem;     //指向数据元素的基地址  int  length;       //线性表的当前长度                                                            }SqList;FILE *out,*in;int  u=0,a=0,b=0,c=0;int i;//打开文件int reload(SqList &L){ if ((out = fopen("E:\\ALL\\cs work\\数据结构\\作业\\student.txt", "r+"))== NULL)    printf("文件打开失败！\n");  rewind(out);        for(int j=0;j<L.length;j++) {  fprintf(out,"%s",L.elem[L.length].no);      fprintf(out,"%s",L.elem[L.length].name);   fprintf(out,"%d",L.elem[L.length].age);      fprintf(out,"%d",L.elem[L.length].sex);      fprintf(out,"%d",L.elem[L.length].price[0]);     fprintf(out,"%d",L.elem[L.length].price[1]);      fprintf(out,"%d",L.elem[L.length].price[2]);      fprintf(out,"%d",L.elem[L.length].price[3]);   }//for     fclose(out);   return OK; }//将文件内容读入顺序表int ToList(SqList &L){   char tn[20]="student.txt";   int i; if((in=fopen(tn,"r"))==NULL) {  printf("不能打开文件：%s\n",tn);  exit(ERROR); } while(!feof(in)) {  fscanf(in,"%s",L.elem[L.length].no);  fscanf(in,"%s",L.elem[L.length].name);  fscanf(in,"%d",L.elem[L.length].sex);  fscanf(in,"%d",L.elem[L.length].age);  fscanf(in,"%d",L.elem[L.length].price[0]);  fscanf(in,"%d",L.elem[L.length].price[1]);  fscanf(in,"%d",L.elem[L.length].price[2]);  fscanf(in,"%d",L.elem[L.length].price[3]);  L.elem[i]=L.elem[L.length];  L.length++;  i++; } fclose(in); return OK;}//逐个显示表中学生信息void show(SqList &L){ cout<<"学生信息如下："<<endl; for(int i=1;i<=L.length;i++){  cout<<"学号"<<L.elem[i].no<<" "<<"姓名："<<L.elem[i].name<<" "     <<"性别："<<L.elem[i].sex<<" "<<"年龄："<<L.elem[i].age<<" "     <<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]         <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl; }}//将学生信息插入表中指定位置  void ListInsert(SqList &L){  int i;  cout<<"请输入要插入的位置："<<endl;  cin>>i;  if(L.length==MAXSIZE)   cout<<"没有内存空间！"<<endl;  else if(i<1||i>L.length+1)   cout<<"输入位置不正确，请检查！"<<endl;  else{   for(int j=L.length;j>=i;j--)    L.elem[j+1]=L.elem[j];   cout<<"请分别输入要插入学生的学号，姓名，性别，年龄，四科成绩："<<endl;   cout<<"学生学号：";       cin>>L.elem[i].no;         cout<<"学生姓名：";      cin>>L.elem[i].name;      cout<<"学生性别：";      cin>>L.elem[i].sex;       cout<<"学生年龄：";      cin>>L.elem[i].age;      cout<<"学生成绩：";      cin>>L.elem[i].price[0];      cin>>L.elem[i].price[1];      cin>>L.elem[i].price[2];      cin>>L.elem[i].price[3];      cout<<endl;   cout<<"插入成功！"<<endl;   cout<<"插入的学生信息为："<<endl;   cout<<"学号："<<L.elem[i].no<<endl;   cout<<"姓名："<<L.elem[i].name<<endl;   cout<<"性别："<<L.elem[i].sex<<endl;   cout<<"年龄："<<L.elem[i].age<<endl;   cout<<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]    <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl;  } }  //删除指定学生的信息Status  ListDelete(SqList &L,int i) { FILE *fp; if(i>=0&&i<=L.length) {  for(int j=i;j<L.length;j++)  {   //将指定位置之后的元素依次往前移   L.elem[j-1]  =L.elem[j];  }  --L.length; } else{  printf("输入的位置有误！"); } fp=fopen("Database.txt","w"); if(fp==NULL) {  printf("文件无法打开!\n"); exit(ERROR); } return OK; }//统计表中学生个数int GetLength(SqList L){ return L.length;}//直接排序void InsertSort(SqList &L){ for(int i=2;i<=L.length;i++){  if(strcmp(L.elem[i].name,L.elem[i-1].name)<0)  {   L.elem[0]=L.elem[i];   L.elem[i]=L.elem[i-1];   for(int j=i-2;strcmp(L.elem[0].name,L.elem[j].name)<0;j--)   {    L.elem[j+1]=L.elem[j];    L.elem[j]=L.elem[0];   }  } } a=1;}//快速排序int Partition(SqList &L,int low,int high)  {     char pivotkey[10];  //设置关键字pivotkey    L.elem[0]=L.elem[low];// 把表的第一个记录作为枢轴    strcpy(pivotkey,L.elem[low].no);//将学号作为关键字放入pivotkey中保存    while(low< high)      {          while((low<high)&&(L.elem[high].no>=pivotkey))              --high;          L.elem[low]=L.elem[high];          while((low<high)&&(L.elem[low].no<=pivotkey))              ++low;          L.elem[high]=L.elem[low];    }      L.elem[low]=L.elem[0];    return low;}  void QSort(SqList &L,int low,int high)  {            if(low<high)      {           int pivotloc=Partition(L,low,high);         QSort(L,low,pivotloc-1); //对低子表递归排序，pivotloc是枢轴位置        QSort(L,pivotloc+1,high); //对高子表递归排序      }  }    void QuickSort(SqList &L)  {     QSort(L,1,L.length);  }     //根据姓名进行折半查找，使用递归，返回学生学号和成绩。int Search_Dname(SqList &L,char a[],int low,int high){ low=1;    high=L.length; int mid=(low+high)/2; if(strcmp(a,L.elem[mid].name)==0) return mid;    if(strcmp(a,L.elem[mid].name)<0)  return Search_Dname(L,a,low,mid-1); if(strcmp(a,L.elem[mid].name)>0) return Search_Dname(L,a,mid+1,high);  return 0;}//根据姓名进行折半查找，不使用递归，返回学生的学号和成绩。int Search_No(SqList &L,char b[]){ int mid; int low=1; int high=L.length;    while(low<=high){  mid=(high+low)/2;     if(strcmp(b,L.elem[mid].name)==0) return mid;  else if(strcmp(b,L.elem[mid].name)<0) high=mid-1;  else low=mid+1; } return 0;}void stop(){ char i; cout<<"您真的要退出程序吗 ？"<<endl; cout<<"1"<<"确定"; cout<<"2"<<"取消"; cin>>i; switch(i){ case '1':cout<<"谢谢使用！"<<endl;exit(0); case '2':break; default:  cout<<"输入错误！"<<endl;  cin>>i;break; }}//主函数void main(){ //freopen("student.txt","r","stdin"); //freopen("student2.txt","w",stdout); //int no; int n; SqList L; while(1){  cout<<"*************欢迎使用学生信息查询系统******************"<<endl;  cout<<"1.读入学生信息（学号，姓名，性别，年龄，成绩）。"<<endl;  cout<<"2.逐个显示学生相关信息。"<<endl;  cout<<"3.插入学生信息到指定位置。"<<endl;  cout<<"4.删除指定位置学生。"<<endl;  cout<<"5.统计表中学生人数。"<<endl;  cout<<"6.直接插入排序按学生姓名排序。"<<endl;  cout<<"7.快速排序按学生学号排序。"<<endl;  cout<<"8.根据姓名进行折半查找。（递归）"<<endl;  cout<<"9.跟学号进行折半查找（非递归）。"<<endl;  cout<<"0.退出系统。"<<endl;  cout<<endl;//设置菜单栏    cout<<"请选择您需要的服务：";  cin>>n;  switch(n)  {  case 1:{   reload(L);   ToList(L);      }  case 2:if(u){   show(L);   getch();      }  case 3:if(u){   ListInsert(L);   getch();      }else       cout<<"请先读入文件！"<<endl;break;  case 4:if(u){   int i;   ListDelete(L,i);   getch();      }else       cout<<"请先读入文件！"<<endl;break;  case 5:{if(u){   int i=GetLength(L);   cout<<"学生总人数为："<<i<<"个"<<endl;break;}  case 6:if(u){   InsertSort(L);   b=0;   cout<<"直接插入排序成功，按姓名从小到大排序为："<<endl;   for(int k=1;k<=L.length;k++){    cout<<"学号"<<L.elem[i].no<<" "<<"姓名："<<L.elem[i].name<<" "     <<"性别："<<L.elem[i].sex<<" "<<"年龄："<<L.elem[i].age<<" "     <<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]         <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl;    getch();   }      }   else    cout<<"请先读入文件！"<<endl;break;      }  case 7:if(u){   QSort(L,1,L.length);   a=1;   cout<<"快速排序成功，按学号从小到大输出如下："<<endl;   for(int k=1;k<=L.length;k++){    cout<<"学号"<<L.elem[i].no<<" "<<"姓名："<<L.elem[i].name<<" "     <<"性别："<<L.elem[i].sex<<" "<<"年龄："<<L.elem[i].age<<" "     <<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]         <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl;   }   getch();      }else       cout<<"请先读入文件！"<<endl;break;  case 8:if(u==0)       cout<<"请先读入文件！"<<endl;       else if(u==1&&a==0)     cout<<"请先使用命令6进行排序。"<<endl;    else{     char a[20];     cout<<"请输入你要查找的学生名字：";     cin>>a;     int i;     i=Search_Dname(L,a,0,L.length);     if(i>=0)      cout<<"您查找的学生个人信息为：学号"<<L.elem[i].no<<" "<<"姓名："<<L.elem[i].name<<" "     <<"性别："<<L.elem[i].sex<<" "<<"年龄："<<L.elem[i].age<<" "     <<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]         <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl;     else      cout<<"学生不存在！"<<endl;     getch();    }break;  case 9:if(u==0)       cout<<"请先读入文件！"<<endl;       else if(u==1&&a==0)     cout<<"请先使用命令7进行排序。"<<endl;    else{     char b[10];     cout<<"请输入您要查找的学生学号：";     cin>>b;     int j=Search_No(L,b);     if(j>=0)      cout<<"您查找的学生个人信息为：学号"<<L.elem[i].no<<" "<<"姓名："<<L.elem[i].name<<" "     <<"性别："<<L.elem[i].sex<<" "<<"年龄："<<L.elem[i].age<<" "     <<"成绩："<<L.elem[i].price[0]<<L.elem[i].price[1]         <<L.elem[i].price[2]<<L.elem[i].price[3]<<endl;     else      cout<<"学生不存在！"<<endl;     getch();    }break;  case 0:cout<<endl;         stop();break;  default:   cout<<"输出错误！"<<endl;break;      }   cout<<endl;      }  }