第16周项目2-用文件保存学生名单

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/**Copyright(C) 2016,计算机与控制工程学院*All rights reserved.*文件名:test.cpp*作者:张志新*完成日期:2016年6月23日*版本号:v1.0**问题描述:用文件保存学生名单*/#include <fstream>#include<iostream>#include<string>#include<cstdlib>using namespace std;class Student{public:    Student() {};    ~Student();    double get_total();    static int get_stu_num();    static double get_total_sum();    friend istream& operator>>(istream &in, Student &s);//重载    friend ostream& operator<<(ostream &out, Student &s);    bool pass();private:    string name;    double cpp;    double math;    double english;    double total;    static int stu_num;    static double total_sum;};int Student::stu_num = 0;double Student::total_sum = 0;Student::~Student()//析构函数{    total_sum-=total;    stu_num--;}double Student::get_total(){    return total;}int Student::get_stu_num(){    return stu_num;}double Student::get_total_sum(){    return total_sum;}istream& operator>>(istream &in, Student &s){    cin>>s.name>>s.cpp>>s.math>>s.english;    s.total=s.cpp+s.math+s.english;    Student::stu_num++;    Student::total_sum+=s.total;    return in;}ostream &operator<<(ostream &out, Student &s){    out<<s.name<<"\t";    out<<s.cpp<<"\t";    out<<s.math<<"\t";    out<<s.english<<"\t";    out<<s.total;    return out;}bool Student::pass(){    return cpp>=60 && math>=60 && english>=60;}int main(){    Student stud[200],t;    string sname;    double total_avg;    int i=0;    ifstream infile("score.dat",ios::in);    if(!infile)//文件打开不成功    {        cerr<<"open error!"<<endl;        exit(1);    }    while(!infile.eof())    {        infile>>stud[i++];    }    infile.close();//关闭文件    if(Student::get_stu_num()>0)    {        total_avg = Student::get_total_sum() / Student::get_stu_num();        ofstream outfile("pass_score.dat",ios::out);        if(!outfile)        {            cerr<<"open error!"<<endl;            exit(1);        }        for(i=0; i<Student::get_stu_num(); i++)        {            if(stud[i].get_total()>total_avg&&stud[i].pass())            {                outfile<<stud[i]<<endl;            }        }        outfile.close();        cout<<"请到文件pass_score.dat中查看名单："<<endl;    }    return 0;}
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