Debug Assertion Failed C++ : Vector subscript out of range - c++

Question

I have made a program that is trying to read a .csv file and calculates the grades of the students.
I have made Student class and in the Main function I make Student type vector to read through the file and store the data in objects. Then I store all my objects in the vector .
The code was working fine, until I made some changes to take the filepath from the user. Now Its not working IDK why.. Kindly take a look into the code.
Student.h
#include <iostream>
#include <string>
using namespace std;
class student {
public:
string CMSID, firstname, lastname;
double quiz1, ass1, ass2, ass3, quiz2, quiz3, oht1, oht2, ESE, aggregate;
student();
student(string cmsid, string fn, string ln, double q1, double a1, double a2, double a3, double q2, double q3, double o1, double o2, double ese);
void calculateAggregate();
};
Students.cpp
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>
#include "students.h"
using namespace std;
student::student() {}
student::student(string cmsid, string fn, string ln, double q1, double a1, double a2, double a3, double q2, double q3, double o1, double o2, double ese) {
CMSID = cmsid;
firstname = fn;
lastname = ln;
quiz1 = quiz1;
quiz2 = quiz2;
quiz3 = quiz3;
ass1 = a1;
ass2 = a2;
ass3 = a3;
oht1 = o1;
oht2 = o2;
ESE = ese;
}
void student::calculateAggregate()
{
aggregate = ((quiz1 + quiz2 + quiz3)*(10.0 / 30.0) + (ass1 + ass2 + ass3)*(10.0 / 30.0) + (oht1)*(20.0 / 50.0) + (oht2)*(20.0 / 50.0) + ESE * (40.0 / 100.0));
}
int main(int argc, char **argv) {
string CMSID, firstname, lastname, quiz1, ass1, ass2, ass3, quiz2, quiz3, oht1, oht2, ESE;
string Name,fileName;
ifstream gradesFile;
cout << "Place your file (.csv) in the program's directory." << endl;
cout << "Make sure that the first two rows of your file does not contain any student's data. " << endl;
cout << "Enter file name with extension(.csv): " ;
// taking filepath or filename input from the user
cin >> fileName;
gradesFile.open(fileName);
//declaring vectors of Type Student and type Double to store the objects of students containing their data (names, quizzes etc)
vector <double> aggregateList;
vector <student> students;
student *st;
//Ignoring the first two rows containing the titles of the columns
getline(gradesFile, Name);
getline(gradesFile, Name);
/// good() returns true if the file is readable and writeable
while (gradesFile.good()) {
try {
getline(gradesFile, CMSID, ',');
getline(gradesFile, firstname, ',');
getline(gradesFile, lastname, ',');
getline(gradesFile, quiz1, ',');
getline(gradesFile, ass1, ',');
getline(gradesFile, ass2, ',');
getline(gradesFile, ass3, ',');
getline(gradesFile, quiz2, ',');
getline(gradesFile, quiz3, ',');
getline(gradesFile, oht1, ',');
getline(gradesFile, oht2, ',');
getline(gradesFile, ESE, '\n');
if (quiz1.compare("") == 0) { // Replacing the empty colums with a 0 to manipulate the data correctly.
quiz1 = "0";
}
if (quiz2.compare("") == 0) {
quiz2 = "0";
}
if (quiz3.compare("") == 0) {
quiz3 = "0";
}
if (ass1.compare("") == 0) {
ass1 = "0";
}
if (ass2.compare("") == 0) {
ass2 = "0";
}
if (ass3.compare("") == 0) {
ass3 = "0";
}
if (oht1.compare("") == 0) {
oht1 = "0";
}
if (oht2.compare("") == 0) {
oht2 = "0";
}
if (ESE.compare("") == 0) {
ESE = "0";
}
// storing the data as student type objects and storing them in the vector <students>
st = new student(CMSID, firstname, lastname, stod(quiz1), stod(ass1), stod(ass2), stod(ass3), stod(quiz2), stod(quiz3), stod(oht1), stod(oht2), stod(ESE));
students.push_back(*st);
}
catch (invalid_argument) {}
}
// Calculating aggregates of all the student objects, and storing them in a separate aggregate list.
for (int j = 0; j < students.size(); j++) {
students[j].calculateAggregate();
aggregateList.push_back(students[j].aggregate);
}
// sorting the aggregateList vector to calculate the Grades correctly
sort(aggregateList.begin(), aggregateList.end());
//Calculating Deciles (10,20,30 percents and so on)
//d1 gives the data item that has 10 percent values below it, d2 has 20 percent values and so on...
double d1 = aggregateList[ceil(((aggregateList.size() + 1)*(0.1)))];
double d2 = aggregateList[ceil(((aggregateList.size() + 1)*(0.2)))];
double d3 = aggregateList[ceil(((aggregateList.size() + 1)*(0.3)))];
double d4 = aggregateList[ceil(((aggregateList.size() + 1)*(0.4)))];
double d5 = aggregateList[ceil(((aggregateList.size() + 1)*(0.5)))];
double d6 = aggregateList[ceil(((aggregateList.size() + 1)*(0.6)))];
double d7 = aggregateList[ceil(((aggregateList.size() + 1)*(0.7)))];
double d8 = aggregateList[ceil(((aggregateList.size() + 1)*(0.8)))];
double d9 = aggregateList[ceil(((aggregateList.size() + 1)*(0.9)))];
//Giving grades
ofstream A, Bplus, B, Cplus, C, Dplus, D, F;
A.open(fileName + "-A Grades.csv ");
Bplus.open(fileName + "-Bplus.csv");
B.open(fileName + "-B Grades.csv");
C.open(fileName + "-C Grades.csv");
Cplus.open(fileName + "-Cplus Grades.csv");
D.open(fileName + "-D Grades.csv");
Dplus.open(fileName + "-Dplus Grades.csv");
F.open(fileName + "-F Grades.csv");
for (int j = 0; j < students.size(); j++) {
if (A.is_open()) {
if (students[j].aggregate > d9) A << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (Bplus.is_open()) {
if (students[j].aggregate > d7 && students[j].aggregate <= d9) Bplus << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (B.is_open()) {
if (students[j].aggregate > d5 && students[j].aggregate <= d7) B << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (Cplus.is_open()) {
if (students[j].aggregate > d4 && students[j].aggregate <= d5) Cplus << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (C.is_open()) {
if (students[j].aggregate > d3 && students[j].aggregate <= d4) C << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (Dplus.is_open()) {
if (students[j].aggregate > d2 && students[j].aggregate <= d3) Dplus << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (D.is_open()) {
if (students[j].aggregate > d1 && students[j].aggregate <= d2) D << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
if (F.is_open()) {
if (students[j].aggregate <= d1) F << students[j].CMSID << "," << students[j].firstname << "," << students[j].lastname << "," << students[j].aggregate << endl;
}
else cout << "File coudln't be made." << endl;
}
A.close();
B.close();
Bplus.close();
C.close();
Cplus.close();
D.close();
Dplus.close();
F.close();
system("pause");
return 0;
}
I have already searched the website for relevant errors, but couldn't understand!
Check the error here.

Answer 1

The error is caused by creating a vector with size n, but accessing elements beyond that.
a vector x of size n has
x[0], x[1], x[2], ..., x[n-2], x[n-1]
Accessing x[n], or x[n+1] will be outside of the range and throw the error.
ceil(((aggregateList.size() + 1)*(0.9)))
Is an expression that can be as large as n for the vector, and can overrun the memory

Answer 2

You need to use a debugger. Fortunately since you are using Visual Studio this is much nicer experience than using gdb.
When the assertion fails click retry in the popup, that will give you the opportunity to inspect the call stack and the values of the variables.
Alternatively if this way it is easier for you you can step through your program line by line and watch the values of the variables change...