我如何退出输出文件.. [英] How do I. Exit out the outputfile..
问题描述
输出文件不想退出。你能帮助我吗？我曾经尝试过，直到没有错误。有什么我想念的吗？我还是个初学者。我需要帮助。
这个问题要求编写一个程序来保存记录并对50名学生进行统计分析。对于每个学生，您将拥有一个10位数的ID，2个测验，2个作业，2个实验室测试，1个测试，1个项目和1个期末考试。学生数据将存储在一系列学生结构中。这个结构有以下字段：
i）字符串：id
ii）3个双数组：测验，屁股，labTest
iii）4双变量：test，proj，final，total
iv）1个char变量：grade。
最多可容纳50名学生。
输入是从文本文件中读取的。文件中的每一行都包含学生ID和2个测验，2个作业，2个实验室测试，1个测试，1个项目和1个期末考试的分数。你的课程必须计算总分并为每个学生分配一个分数
我尝试过：
the output file does not want to exit out . can you help me? i had tried until got no error only . is there anything thai i have miss? and i still a beginner . i need help.
the question asks to Write a program to keeps records and performs statistical analysis for a class of 50 students. For each student you will have a 10-digit ID, 2 quizzes, 2 assignments, 2 lab tests, 1 test, 1 project and one final exam. The student data are to be stored in an array of student structures. This structure has the following fields:
i)A string : id
ii)3 double arrays : quiz, ass, labTest
iii)4 double variables : test, proj, final, total
iv)1 char variable: grade.
Provide for up to 50 students.
The input is read from a text file. Each line in the file contains a student ID and the scores for 2 quizzes, 2 assignments, 2 lab tests, 1 test, 1 project and one final exam, in order. Your program must calculate the total scores and assign a grade for each student
What I have tried:
#include<iostream>
#include<fstream>
#include<iomanip>
#include<string>
#include<cstdlib>
using namespace std;
struct DATA
{
string id;
double quiz[2];
double ass[2];
double labTest[2];
double test;
double proj;
double final;
double total;
double midTerm;
char grade;
};
int main()
{
ifstream inputfile("studentResults.txt", ios::in);
ofstream outputfile("result.txt", ios::out);
if (!inputfile)
{
cerr << "the file could not be opened";
exit(1);
}
if (!outputfile)
{
cerr << "the file could not be opened";
exit(1);
}
cout << setw(10) << "Matrix Num" << setw(10) << "Quiz(5%)" << setw(10) << "Ass(15%)" << setw(10) << "LabTests(20%)" << setw(10)
<< "Project(15%)" << setw(10) << "MidTerm(15%)" << setw(10) << "Final(30%)" << setw(10) << "Total(100%) " << setw(10) << "Grade" << endl;
void studentGrade();
void countGrade();
void outputResult();
DATA student[50]; int i;
for (i = 0;i < 50;i++)
while (inputfile >> student[i].id >> student[i].quiz[0] >> student[i].quiz[1] >> student[i].ass[0] >> student[i].ass[1] >> student[i].labTest[0]
>> student[i].labTest[1] >> student[i].proj >> student[i].midTerm >> student[i].final >> student[i].total >> student[i].grade)
{
cout << student[i].id << student[i].quiz[0] << student[i].quiz[1] << student[i].ass[0] << student[i].ass[1] << student[i].labTest[0]
<< student[i].labTest[1] << student[i].proj << student[i].midTerm << student[i].final << student[i].total << student[i].grade;
}
cout << endl;
}
void studentGrade(DATA student[])
{
for (int i = 0; i < 50; i++)
{
student[i].total = student[i].midTerm + student[i].proj + student[i].final +
((student[i].quiz[0] + student[i].quiz[1]) / 2) + (student[i].ass[0] + student[i].ass[1]) / 2 +
(student[i].labTest[0] + student[i].labTest[1]) / 2;
if (student[i].total >= 90 && student[i].total <= 100)
student[i].grade = 'A';
else if (student[i].total >= 80)
student[i].grade = 'B';
else if (student[i].total >= 60)
student[i].grade = 'C';
else if (student[i].total >= 40)
student[i].grade = 'D';
else
student[i].grade = 'F';
}
}
void countGrade(DATA student[], int[])
{
int i, a = 0, b = 0, c = 0, d = 0, f = 0;
for (i = 0;i < 50;i++) {
if (student[i].grade == 'A')
a++;
else if (student[i].grade == 'B')
b++;
else if (student[i].grade == 'C')
c++;
else if (student[i].grade == 'D')
d++;
else if (student[i].grade == 'F')
f++;
}
}
void outputResult(DATA student[], int g[5])
{
ofstream outputfile("result.txt", ios::out);
if (!outputfile)
{
cerr << "the file could not be opened";
exit(1);
}
int i;
for (int i = 0;i < 50;i++)
{
student[i].quiz[2] = (student[i].quiz[0] + student[i].quiz[1]) / 2 * 0.05;
student[i].ass[2] = (student[i].ass[0] + student[i].ass[1]) / 2 * 0.15;
student[i].labTest[2] = (student[i].labTest[0] + student[i].labTest[1]) / 2 * 0.2;
}
outputfile << setw(10) << "Matrix Num" << setw(10) << "Quiz(5%)" << setw(10) << "Ass(15%)" << setw(10) << "LabTests(20%)" << setw(10)
<< "Project(15%)" << setw(10) << "MidTerm(15%)" << setw(10) << "Final(30%)" << setw(10) << "Total(100%) " << setw(10) << "Grade" << endl;
for (int i = 0;i < 50;i++)
{
outputfile << setw(10) << setw(10) << student[i].id << setw(10) << student[i].quiz[2] << setw(10) << student[i].ass[2]
<< setw(10) << student[i].ass[2] << setw(10) << student[i].labTest[0] << setw(10) << student[i].labTest[1]
<< setw(10) << student[i].proj << setw(10) << student[i].midTerm << setw(10) << student[i].final
<< setw(10) << student[i].total << setw(10) << student[i].grade << endl;
}
outputfile << endl;
outputfile << "Total Students for Grade A : " << g[0] << endl;
outputfile << "Total Students for Grade B : " << g[1] << endl;
outputfile << "Total Students for Grade C : " << g[2] << endl;
outputfile << "Total Students for Grade D : " << g[3] << endl;
outputfile << "Total Students for Grade F : " << g[4] << endl;
outputfile << "\nA : ";
for (i = 0;i < g[0];i++)
outputfile << "* ";
outputfile << "\nB : ";
for (i = 0;i < g[1];i++)
outputfile << "* ";
outputfile << "\nC : ";
for (i = 0;i < g[2];i++)
outputfile << "* ";
outputfile << "\nD : ";
for (i = 0;i < g[3];i++)
outputfile << "* ";
outputfile << "\nF : ";
for (i = 0;i < g[4];i++)
outputfile << "* ";
outputfile.close();
}
推荐答案
嗯......你已经创建了函数，但实际上并没有调用他们！
看看你的主要功能，你会看到你只引用studentGrade，countGrade和outputResult作为函数声明，你不会在任何时候实际调用它们，传递所需的参数。
代码中的某处你需要这样的行：
Well... You've created functions, but you don't actually call them!
Look at your main function, and you will see that you only referencestudentGrade,countGrade, andoutputResultas function declarations, you don't at any point actually call them, passing the required parameters.
Somewhere in your code you will need lines like this:
studentGrade(student);
countGrade(student, arrayOfGrades);和
outputResult(student, arrayOfGrades);（你必须修改 countGrade 实际填写成绩数组，而不是在退出时丢弃信息。）
(and you will have to modify countGrade to actually fill the grades array instead of discarding the information when it exits).
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