十七周任务1

#include
#include 
using namespace std;
class Student
{public:
Student(void){}
Student(char nam[20], double cs, double mas, double ens, double all, double avs):cscore(cs), mathscore(mas), englishscore(ens), allscore(all), averagescore(avs){strcpy(name,nam);}
void display();

friend void cin_score(Student stud[]);

friend void out_score(Student stud[]);

private:
	char name[20];
	double cscore;
	double mathscore;
	double englishscore;
	double allscore;
	double averagescore;
};

void Student::display()
{
	cout << name << '\t' << cscore << '\t' << mathscore << '\t' << englishscore << '\t' << allscore << '\t' << averagescore << endl; 
}

void cin_score(Student stud[])
{
	ifstream infile("score.dat",ios::in);  

	if(!infile)
	{	cerr<<"open score.dat error!"<> stud[i].name >> stud[i].cscore >> stud[i].mathscore >> stud[i].englishscore;
		}

		stud[i].allscore = stud[i].cscore + stud[i].mathscore + stud[i].englishscore;
		stud[i].averagescore = stud[i].allscore / 3;
	}
	infile.close( );
}

void out_score(Student stud[])
{
	ofstream outfile("binary_score.dat",ios::binary);

	if(!outfile)
	{	cerr<<"open binary_score.dat error!"<