我对c ++有些新意，我们的课程只是简单地调试了一下。这可能是我的第10次做，我已经花了一周时间，已经对网络进行了大量的研究，我只是不了解调试，以了解如何修复我的代码。该程序应该是这样的文件：
TTFTFTTTFTFTFFTTFTTF
ABC54102 T FTFTFTTTFTTFTTF TF
DEF56278 TTFTFTTTFTFTFFTTFTTF
ABC42366 TTFTFTTTFTFTFFTTF
ABC42586 TTTTFTTT TFTFFFTF
当它读取文件时，它应该输出学生ID，他们在每个问题上回答的内容以及每个学生的成绩。我的问题是，我对调试知之甚少，VS在我提供的代码末尾不断抛出异常。我只是学习如何使用动态数组，所以我知道它与我使用它们有关，因为我的程序在我的其他c ++类中工作得很好但我不得不改变它以使用动态数组来实现这个项目。 / p>
我的计划有什么问题？我已经对网络进行了研究并反复阅读了本书中的章节，我无法弄明白。
#include <iostream>
#include <string>
#include <fstream>
#include <stdlib.h>
#include <cstddef>
using namespace std;
// function prototypes
void readFile(ifstream& inFile);
char assignGrade(int score, int numQues);
int main()
{
int numQues = 20;
int numStud = 0;
string *studentIDs;
studentIDs = new string[numStud];
char *correctAnswers;
correctAnswers = new char[numStud];
char *studentAnswers;
studentAnswers = new char[numQues];
ifstream inFile;
cout << "\nRedo Programming Exercise Six of Chapter Eight\nUsing Dynamic Arrays..." << endl;
cout << "\nPlease Enter the Number of Students: ";
cin >> numStud;
cout << endl;
readFile(inFile);
inFile.getline(correctAnswers, '/n'); // read the correct answers first
for (int i = 0; i < numStud; i++) // loop students
{
inFile >> studentIDs[i]; // get the student ID
inFile.get(); // discard the space between the student ID and the answer
for (int j = 0; j < numQues; j++) // loop questions
{
studentAnswers[j] = inFile.get(); // get the student's answers
}// end for
cout << "Student ID: " << studentIDs[i] << endl; // output student id
int score = 0; // declare and initialize score to zero
cout << "Answers: "; // display "Answers: "
for (int j = 0; j < numQues; j++) // loop each question
{
cout << studentAnswers[j]; // output student's answers
if (studentAnswers[j] == correctAnswers[j]) // if student answer equals correct answer
score += 2; // correct answer
else if (studentAnswers[j] != correctAnswers[j] && studentAnswers[j] != ' ')
score -= 1; // incorrect answer but not a blank
else if (studentAnswers[j] == ' ')
score = 0;
delete[] studentAnswers;
}// end for
if (score < 0)
score = 0; // don't allow for negative scores
cout << endl; // new line, housekeeping
char grade = assignGrade(score, numQues); // call assignGrade function
cout << "Grade: " << grade << "\n" << endl; // display grade
}// end for
delete[] studentIDs;
system("pause");
return(0);
}
void readFile(ifstream& inFile)
{
inFile.open("Ch12_Ex2Data.txt"); // use inFile to open Ch8_Ex6Data.txt
if (!inFile) // if the file can't be opened or it is corrupt
{
cout << "There was an error opening the input file...\nPlease check file and try again!\n" << endl; // display error message
system("pause");
exit(1); // exit the program
}
} // end readFile function
char assignGrade(int score, int numQues)
{
double percentScore = static_cast<double>(score) / (numQues * 2); // calculate the score percentage
cout << "Score: " << percentScore * 100 << "%" << endl; // display the score
if (percentScore >= 0.9) // if score is greater than or equal to 90%, return A
return 'A';
else if (percentScore >= 0.8) // if score is greater than or equal to 80%, return B
return 'B';
else if (percentScore >= 0.7) // if score is greater than or equal to 70%, return C
return 'C';
else if (percentScore >= 0.6) // if score is greater than or equal to 60%, return D
return 'D';
else // any score lower thn 60%, return F
return 'F';
} // end assignGrade function
它在调试器中不断破坏： static void __CLRCALL_OR_CDECL assign（_Elem＆amp; _Left，const _Elem＆amp; _Right） _NOEXCEPT {//分配一个元素 _Left = _Right; }
答案 0 :(得分：0)
// Redo Programming Exercise Six of Chapter Eight
// Using Dynamic Arrays -- C++ Advanced
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
// function prototype
void readFile(ifstream& inFile, string fileName);
int main()
{
// variables, pointers and dynamic arrays
int numStud = 200; // stores the number of students, max students was 200
int numQues = 20; // stores the number of questions on test
string *studentIDs; // pointer variable for studentIDs dynamic array
char *correctAnswers; // pointer variable for correctAnswers dynamic array
correctAnswers = new char[numQues]; // correctAnswers dynamic char array
char *studentAnswers; // pointer variable for studentAnswers dynamic array
studentAnswers = new char[numQues]; // studentAnswers dynamic char array
char *fileName; // pointer variable for fileName dynamic char array
fileName = new char[25]; // fileName dynamic char array
ifstream inFile; // input stream variable inFile
// display message to explain the program
cout << "\nJames Flowers - Chapter 12 - Programming Exercise 2" << endl;
cout << "\nRedo Programming Exercise Six of Chapter Eight\nUsing Dynamic Arrays..." << endl;
// request file name for fileName dynamic char array
cout << "\nPlease Enter the File Name (Ch12_Ex2Data.txt): ";
cin >> fileName;
cout << endl;
// call readFile function to read the file
readFile(inFile, fileName);
// request number of students for studentIDs dynamic char array and some calculations
cout << "\nHow many students took this test? (4): ";
cin >> numStud;
cout << endl;
studentIDs = new string[numStud]; // create studentIDs dynamic char array
inFile.getline(correctAnswers, '/n'); // read the correct answers first
for (int i = 0; i < numStud; i++) // loop students
{
inFile >> studentIDs[i]; // get the student ID
inFile.get(); // discard the blank space
inFile.getline(studentAnswers, '/n'); // get the student's test answers
cout << "Student ID: " << studentIDs[i] << endl; // output student id
int score = 0; // declare and initialize score to zero
cout << "Answers: "; // display "Answers: "
for (int j = 0; j < numQues; j++) // loop each question
{
cout << studentAnswers[j]; // output student's answers
if (studentAnswers[j] == correctAnswers[j]) // if student answer is correct
score += 2; // add 2 to score
else if (studentAnswers[j] != correctAnswers[j] && studentAnswers[j] != ' ') // incorrect answer but not blank
score -= 1; // subtract 1 from score
else if (studentAnswers[j] == ' ') // if question left blank
score -= 0; // nothing subtracted from score
studentAnswers[j] = ' '; // clear each indice for next student
}// end for
cout << endl; // new line, housekeeping
char grade = 0; // char variable grade initialized to 0
double percentScore = static_cast<double>(score) / (numQues * 2); // calculate the score percentage
cout << "Score: " << percentScore * 100 << "%" << endl; // display the score
if (percentScore >= 0.9) // if score is greater than or equal to 90%, return A
grade = 'A'; // grade = A
else if (percentScore >= 0.8) // if score is greater than or equal to 80%, return B
grade = 'B'; // grade = B
else if (percentScore >= 0.7) // if score is greater than or equal to 70%,
grade = 'C'; // grade = C
else if (percentScore >= 0.6) // if score is greater than or equal to 60%,
grade = 'D'; // grade = D
else // any score lower than 60%,
grade = 'F'; // grade = F
cout << "Grade: " << grade << "\n" << endl; // display grade
}// end for
system("pause"); // pause for readability
return(0);
}// end main
// readFile function reads the file, if not displays error message
void readFile(ifstream& inFile, string fileName)
{
inFile.open(fileName); // use inFile to open input file
if (!inFile.is_open()) // if the file can't be opened or it is corrupt
{
cout << "There was an error opening the input file...\nPlease check file name and try again!\n" << endl; // display error message
system("pause"); // pause for readability
exit(1);
}// end if
} // end readFile function