【生生被气死的一周】头秃

逃离我推掉我的手 2022-01-09 04:23 201阅读 0赞

1 //**************************************************************************************************************
      2 //作者：
      3 //日期：2018/3/19
      4 //学号：
      5 //题号：5-5
      6 //题目：编写一个程序，实现以下功能：
      7 
      8 //      1)输入一系列的学生数据（包括学生的学号、姓名和成绩等基本信息），将学生信息写入二进制文件student.dat中。
      9 
     10 //      2)从student.dat文件中读出这些数据并显示出来。
     11 
     12 //      3)在student.dat文件中按姓名进行查询，如输入“李”，则将所有姓“李”的学生的   数据显示出来。
     13 
     14 //      4)可对指定学生的数据进行修改。
     15 
     16 //      5)可以删除指定的学生数据。
     17 
     18 //**************************************************************************************************************
     19 
     20 
     21 
     22 #include<iostream>
     23 #include<fstream>
     24 #include<stdlib.h>
     25 #include<cstring>
     26 using namespace std;
     27 struct Std
     28 {
     29     char name[20];
     30     char id[20];
     31     char score[5];
     32 };
     33 void getinfo(char filename[]);
     34 void showinfo(char filename[]);
     35 void searchinfo(char filename[]);
     36 void editinfo(char filename[]);
     37 void deleteinfo(char filename[]);
     38 
     39 int main()
     40 {
     41     fstream student;
     42     char choice;
     43     char filename[20];
     44     cout << "Please type in the filename:";
     45     cin.getline(filename,20);
     46     cout << endl;
     47     while(true)
     48     {
     49         cout << "Please type down the manipulation code:\nA.Input information\tB.Show information\tC.Search\tD.Edit\tE.Delete\tF.Exit\n";
     50         cout << endl;
     51         cin >> choice;
     52         switch(choice)
     53         {
     54             case'A':
     55             case'a':getinfo(filename);break;
     56             case'B':
     57             case'b':showinfo(filename);break;
     58             case'C':
     59             case'c':searchinfo(filename);break;
     60             case'D':
     61             case'd':editinfo(filename);break;
     62             case'E':
     63             case'e':deleteinfo(filename);break;
     64             case'F':
     65             case'f':exit(0);
     66         }
     67         cout << endl;
     68     }
     69     return 0;
     70 }
     71 
     72 void getinfo(char filename[])
     73 {
     74     fstream student;
     75     student.open(filename,ios::out|ios::binary);
     76     if(!student)
     77     {
     78         cout << "Error!";
     79         exit(0);
     80     }
     81     int count;
     82     cout << "How many student's information would you like to input?";
     83     cin >> count;
     84     Std *Student;
     85     Student = new struct Std[count];
     86     for(int i=0;i<count;i++)
     87     {
     88         cout << "Please input student "<<i+1<<" 's name:";
     89         cin.get();
     90         cin.getline(Student[i].name,20);
     91         cout << "Please input student "<<i+1<<" 's id:";
     92         cin.getline(Student[i].id,20);
     93         cout << "Please input student "<<i+1<<" 's score:";
     94         cin >> Student[i].score;
     95         student.write((char*)&Student[i],sizeof(Student[i]));
     96     }
     97     cout << "Done.";
     98     delete[]Student;
     99     student.close();
    100 }
    101 
    102 void showinfo(char filename[])
    103 {
    104     fstream student;
    105     student.open(filename,ios::in|ios::binary);
    106     if(!student)
    107     {
    108         cout << "Error!";
    109         exit(0);
    110     }
    111     Std Student;
    112     student.read((char*)&Student,sizeof(Student));
    113     while(!student.eof())
    114     {
    115         cout << "name:";
    116         cout << Student.name <<endl;
    117         cout << "id:";
    118         cout << Student.id <<endl;
    119         cout << "score:";
    120         cout << Student.score <<endl;
    121         student.read((char*)&Student,sizeof(Student));
    122     }
    123     cout << "Above are all the information."<<endl;
    124     student.close();
    125 }
    126 
    127 void searchinfo(char filename[])
    128 {
    129     fstream student;
    130     Std Student;
    131     student.open(filename,ios::in|ios::binary);
    132     if(!student)
    133     {
    134         cout << "Error!";
    135         exit(0);
    136     }
    137     char ch,Name;
    138     cout << "Please input the first name:";
    139     cin >> Name;
    140     long position = student.tellg();
    141     cout << "position:"<<position<<endl;
    142     student.seekg(0L,ios::beg);
    143     student.get(ch);
    144     cout << "ch:"<<ch<<endl;
    145     //cout << "\nch:"<<ch<<endl;
    146     position = student.tellg();
    147     cout << "position:"<<position<<endl;
    148     student.seekg(0L,ios::beg);
    149     long current_pos = 0L;
    150     while(!student.eof())
    151     {
    152         if(ch == Name)
    153         {
    154             cout << "ch:"<<ch<<endl;
    155             student.read((char*)&Student,sizeof(Student));
    156             long position;
    157             position = student.tellg();
    158             cout << "position:"<<position<<endl;
    159             cout << "name:";
    160             cout << Student.name <<endl;
    161             cout << "id:";
    162             cout << Student.id <<endl;
    163             cout << "score:";
    164             cout << Student.score <<endl;
    165             student.seekg(-(sizeof(Student)),ios::cur);
    166             position = student.tellg();
    167             cout << "position:"<<position<<endl;
    168         }
    169         current_pos = current_pos + sizeof(Student);
    170         student.seekg(current_pos,ios::cur);
    171   //      long position = student.tellg();
    172  //           cout << "position:"<<position<<endl;
    173         //student.seekg(1L,ios::cur);
    174         //cin.ignore();
    175         //position = student.tellg();
    176         //cout << "position:"<<position<<endl;
    177  //       student.get(ch);
    178  //       position = student.tellg();
    179  //           cout << "position:"<<position<<endl;
    180   //      student.seekg(-sizeof(ch),ios::cur);
    181    //     position = student.tellg();
    182 //s            cout << "position:"<<position<<endl;
    183     }
    184     cout << "Above are all the information that you are looking for."<<endl;
    185     student.close();
    186 }
    187 
    188 void editinfo(char filename[])
    189 {
    190     fstream student;
    191     Std Student;
    192     student.open(filename,ios::in|ios::out|ios::binary);
    193     if(!student)
    194     {
    195         cout << "Error!";
    196         exit(0);
    197     }
    198     char editid[20];
    199     cout << "Please input the id of the student whose information needs to be edited:";
    200     cin >> editid;
    201     student.seekg(0L,ios::beg);
    202     student.seekg(sizeof(Student.name),ios::beg);
    203     student.seekp(0L,ios::beg);
    204     student.read((char*)&Student.id,sizeof(Student.id));
    205     while(!student.eof())
    206     {
    207         if(strcmp(editid,Student.id)==0)
    208         {
    209             student.seekg(-sizeof(Student.id)-sizeof(Student.name),ios::cur);
    210             student.read((char*)&Student,sizeof(Student));
    211             cout << "The information of the student:"<<endl;
    212             cout << "name:"<<Student.name<<endl;
    213             cout << "id:"<<Student.id<<endl;
    214             cout << "score:"<<Student.score<<endl;
    215             cout << "Now please input the new information:";
    216             cout << "name:";
    217             cin >> Student.name;
    218             cout << "id:";
    219             cin >> Student.id;
    220             cout << "score:";
    221             cin >> Student.score;
    222             student.write((char*)&Student,sizeof(Student));
    223             break;
    224         }
    225         student.seekg(sizeof(Student),ios::cur);
    226         student.seekp(sizeof(Student),ios::cur);
    227     }
    228     cout << "Done.";
    229     student.close();
    230 }
    231 
    232 void deleteinfo(char filename[])
    233 {
    234     fstream student;
    235     Std Student;
    236     student.open(filename,ios::in|ios::out|ios::binary);
    237     if(!student)
    238     {
    239         cout << "Error!";
    240         exit(0);
    241     }
    242     char deleid[20];
    243     cout << "Please input the id of the student whose information needs to be erased:";
    244     cin >> deleid;
    245     student.seekg(0L,ios::beg);
    246     student.seekg(sizeof(Student.name),ios::beg);
    247     student.seekp(0L,ios::beg);
    248     student.read((char*)&Student.id,sizeof(Student.id));
    249     while(!student.eof())
    250     {
    251         if(strcmp(deleid,Student.id)==0)
    252         {
    253             student.seekg(-sizeof(Student.id)-sizeof(Student.name),ios::cur);
    254             student.read((char*)&Student,sizeof(Student));
    255             cout << "The information of the student:"<<endl;
    256             cout << "name:"<<Student.name<<endl;
    257             cout << "id:"<<Student.id<<endl;
    258             cout << "score:"<<Student.score<<endl;
    259             cout << "type 'd' to delete this student's information:";
    260             char code;
    261             cin >> code;
    262             if(code == 'd')
    263             {
    264                 strcpy(Student.name,0);
    265                 strcpy(Student.id,0);
    266                 strcpy(Student.score,0);
    267             }
    268             student.write((char*)&Student,sizeof(Student));
    269             break;
    270         }
    271         student.seekg(sizeof(Student),ios::cur);
    272         student.seekp(sizeof(Student),ios::cur);
    273     }
    274     cout << "Done.";
    275     student.close();
    276 }

转载于:https://www.cnblogs.com/Evanscabin/p/8652931.html