C++程序设计实验报告(八十四) --- 第十七周任务一

/* (程序头部注释开始)
* 程序的版权和版本声明部分
* Copyright (c) 2012, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称：二进制文件读入读出

* 作 者： 刘镇
* 完成日期： 2012 年 06 月 10 日
* 版 本 号： 1.080

* 对任务及求解方法的描述部分
* 输入描述： ......

* 问题描述： ......

* 程序输出： ......

* 程序头部的注释结束
*/ 

#include<iostream>  #include<iomanip>#include<string>  #include<fstream>  using namespace std;  class Student  {  public:  Student();  Student(string name, double cpp, double math, double English);  double all_score();  double ave_score();  void read_score(ifstream &in);  void write_score(ofstream &out);  void display();  private:  string name;  double score_cpp;  double score_math;  double score_English;  double score_all;  double score_average;  };  Student::Student()  {  this->name = "0000";  this->score_cpp = 0;  this->score_math = 0;  this->score_English = 0;  }  Student::Student(string name, double cpp, double math, double English)  {  this->name = name;  this->score_cpp = cpp;  this->score_math = math;  this->score_English = English;  }  void Student::display()  {  this->all_score();this->ave_score();cout << setprecision(1) << setiosflags(ios::fixed);cout << "name: " << setw(3) << this->name << '\t' << "c++: " << setw(3) <<this->score_cpp<< '\t' << "English: " << setw(3) << this->score_English << '\t' << "Math:" << setw(3) << this->score_math << '\t' << "All score: " << this->score_all;cout << '\t'<< "Average score : " << setw(3) << this->score_average << endl;  }  double Student::all_score()  {  this->score_all = this->score_cpp + this->score_math + this->score_English;  return this->score_all;  }  double Student::ave_score()  {  this->score_average = (this->score_cpp + this->score_math + this->score_English) / 3;  return this->score_average;  }  void Student::read_score(ifstream &in)  {  in >> this->name >> this->score_cpp >> this->score_math >> this->score_English;  }  void Student::write_score(ofstream &out)  {  out << setprecision(1) << setiosflags(ios::fixed);out << this->name << '\t' << this->score_cpp << '\t' << this->score_math << '\t' << this->score_English << '\t' << this->score_all << '\t' << this->score_average << endl;  }  void readfile(Student * s, int num)  {  ifstream infile("score.dat",ios::in);  if(!infile)  {  cerr << "open error!" << endl;  exit(1);  }  for(int i = 0; i < num; ++i)  {  s[i].read_score(infile);  }  infile.close();  }  void Readfile(Student * s, int num)  {  ifstream infile("binary_score.dat",ios::in|ios::binary);  if(!infile)  {  cerr << "open error!" << endl;  abort();  }  for(int i = 0; i < num; ++i)  {  infile.read((char *) & s[i], sizeof(s[i]));  }  infile.close();  }  void Writefile(Student * s, int num)  {  ofstream outfile("binary_score.dat",ios::out|ios::binary);  if(!outfile)  {  cerr << "open error!" << endl;  abort();  }  for(int i = 0; i < num; ++i)  {  outfile.write((char *) & s[i], sizeof(s[i]));  }  outfile.close();  }  void writefile(Student * s, int num)  {  ofstream outfile("binary_score2.dat",ios::out);  if(!outfile)  {  cerr << "open error!" << endl;  abort();  }  for(int i = 0; i < num; ++i)  {  s[i].write_score(outfile);  }  outfile.close();  }  int main()  {  Student stu[101], my_score("刘镇", 100, 100, 100);  readfile(stu, 100);  Writefile(stu, 100);  Readfile(stu, 100);  stu[100] = my_score;  for(int i = 0; i < 101; ++i)  {  stu[i].display();  }  writefile(stu, 101);  system("pause");  return 0;  }  

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