冒泡排序崩溃程序c++

所以我一直在为class做一个项目，一切都很顺利，直到我不得不按姓氏升序对信息进行排序。更详细地说，在我的程序中，我应该接受文件输入，将其应用于我认为合适的任何类型的变量，通过将他们的答案与答案关键字进行比较来计算他们的成绩，然后按姓氏对条目进行排序。事不宜迟，这是我的代码！（温和）

#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <algorithm>
const int TEST_SIZE = 10;
using namespace std;
struct StudentInfo
{
int id;
string fName;
string lName;
char testAnswers[10];
int totalPoints = 0;
int avg = 0;
char letterGrade;
};

void inputInfo(char[], StudentInfo[]);
void calcGrade(char[], StudentInfo[]);
void bubbleSort(StudentInfo[]);
void outputInfo(StudentInfo[]);
int main()
{
StudentInfo studentInfo[10];
string temp;
char answerKey[10];
inputInfo(answerKey, studentInfo);
calcGrade(answerKey, studentInfo);
bubbleSort(studentInfo);
outputInfo(studentInfo);
return 0;
}
void inputInfo(char answerKey[], StudentInfo studentInfo[])
{
cout << "Please enter the 10-question answer key: n";
for(int i = 0; i < TEST_SIZE; i++)
    {
        cout << "Question " << i+1 << "n";
        cin >> answerKey[i];
    }
    ifstream inFile("student.txt");
    for(int i = 0; i < TEST_SIZE; i++)
        {
            inFile >> studentInfo[i].id;
            inFile >> studentInfo[i].fName;
            inFile >> studentInfo[i].lName;
            for(int j = 0; j < TEST_SIZE; j++){
            inFile >> studentInfo[i].testAnswers[j];
            }
        }
}
void calcGrade(char answerKey[], StudentInfo studentInfo[])
{
for(int i = 0; i < TEST_SIZE; i++)
    {
        for(int j = 0; j < TEST_SIZE; j++)
            {
                if(studentInfo[i].testAnswers[j] == answerKey[j])
                    {
                        studentInfo[i].totalPoints += 5;
                    }
                    studentInfo[i].avg = studentInfo[i].totalPoints * 2;
                    if(studentInfo[i].avg >= 90)
                        {
                            studentInfo[i].letterGrade = 'A';
                        }
                    else if(studentInfo[i].avg >= 80)
                        {
                            studentInfo[i].letterGrade = 'B';
                        }
                    else if(studentInfo[i].avg >= 70)
                        {
                            studentInfo[i].letterGrade = 'C';
                        }
                    else if(studentInfo[i].avg >= 60)
                        {
                            studentInfo[i].letterGrade = 'D';
                        }
                    else
                        {
                            studentInfo[i].letterGrade = 'F';
                        }
            }
        }
}
void bubbleSort(StudentInfo studentInfo[])
{
StudentInfo temp;
int i;
int j;
for(i = 0; i < (TEST_SIZE-1); i++)
    {
        for(j = 0; j < TEST_SIZE; j++)
            {
                if(studentInfo[j].lName < studentInfo[j-1].lName)
                    {
                        temp = studentInfo[j];
                        studentInfo[j] = studentInfo[j-1];
                        studentInfo[j-1] = temp;
                    }
            }
    }
}
void outputInfo(StudentInfo studentInfo[])
{
cout << setprecision(1) << fixed;
cout << "Student IDtStudent NametAnswerstTotal PtstAveraget   Letter Grade" << endl;
for(int i = 0; i < TEST_SIZE; i++)
    {
        cout << studentInfo[i].id << "t";
        cout << studentInfo[i].lName << " ";
        cout << studentInfo[i].fName << "t";
        for(int j = 0; j < TEST_SIZE; j++)
            {
                cout << studentInfo[i].testAnswers[j];
            }
        cout << "t" << studentInfo[i].totalPoints << "t";
        cout << studentInfo[i].avg << "t";
        cout << studentInfo[i].letterGrade << "n";
    }
}

在我微薄的能力范围内，我尝试了一切，但我的程序总是崩溃。假设在气泡排序过程中，因为没有该部分，它可以正常工作。如果有人能告诉我我错在哪里，我将不胜感激。很抱歉给您带来不便。