Styjun

Currently trying to run the program I've written and getting the error "Run-Time Check Failure #2 - Stack around the variable 'midtermgrade' was corrupted."

I have no idea what to do to fix it, very new to programming and got thrown into a C++ course that I certainly did not have the background for.

Using Visual Studio 2017.

Code is supplied below.

#include <iomanip>
#include <iostream>
#include <fstream>
#include <string> 

using namespace std;

double mean(int v[], int size);
// PRE: size of array > 0
// POST: return average of values in array

double stddev(int v[], int size, double m);
// PRE: size of array > 0, 0 <= m <= 100
// POST: return standard deviation of values in array with mean m

char letter(int score, double m, double s);
// PRE: 0 <= score, m, s <= 100
// POST: return letter grade for score with mean m and standard deviation s

string code(string id, string lastname, string firstname);
// PRE: id is seven digit identification
// POST: return code of first letter of last name, first letter of first name, last two digits of id


int main()

 ifstream fin;
 ofstream fout;
 fin.open("grades.txt");
 fout.open("grades.txt");
 const int CAPACITY = 25; // capacity of the array
 string codes[CAPACITY]; // array of id codes
 int midterms[CAPACITY]; // array of midterm grades
 int finals[CAPACITY]; // array of final grades
 string id; // 6-digit id code
 string lastname;
 string firstname; // Student's year of school
 int midterm;
 int final;
 string idcode;
 double finalmean; // Average grade on the final
 double finalstddev; // Standard deviation among final grades
 double midtermmean; // Average grade on the midterm
 double midtermstddev; // Standarn deviation among midterm grades
 char finalgrade[CAPACITY]; // An array of the letter grades for the final
 char midtermgrade[CAPACITY]; // An array of the letter grades for the midterm
 int ct = 0;
 while (ct < CAPACITY && fin >> id >> lastname >> firstname >> midterm >> final)
 
 midterms[ct] = midterm;
 finals[ct] = final;
 idcode = code(id, lastname, firstname);
 codes[ct] = idcode;

 ++ct;
 
 finalmean = mean(finals, CAPACITY);
 midtermmean = mean(midterms, CAPACITY);
 finalstddev = stddev(finals, CAPACITY, finalmean);
 midtermstddev = stddev(midterms, CAPACITY, midtermmean);
 for (int i = 0; i <= CAPACITY; i++)
 
 finalgrade[i - 1] = letter(finals[i - 1], finalmean, finalstddev);
 midtermgrade[i - 1] = letter(midterms[i - 1], midtermmean, midtermstddev);
 
 fout << "Grade Calculations" << endl << "By ----" << endl;
 for (int i = 1; i <= CAPACITY; i++)
 
 fout << setprecision(1);
 fout << setw(15) << codes[i - 1] << setw(15) << midterms[i - 1]
 << midtermgrade[i - 1] << setw(15) << finals[i - 1]
 << finalgrade[i - 1] << endl;
 
 fout << endl << endl;
 fout << "The class mean for the midterm exam was a " << midtermmean << endl;
 fout << "The standard deviation amongst the midterm exams was +/- " << midtermstddev << endl;
 fout << endl << endl;
 fout << "The class mean for the final exam was a " << finalmean << endl;
 fout << "The standard deviation amongst the final exams was +/- " << finalstddev << endl;
 fin.close();
 fout.close();
 return 0;




string code(string id, string lastname, string firstname)
// PRE: id is seven digit identification
// POST: return code of first letter of last name, first letter of first name, last two digits of id

 char firstletterfirst = firstname[0];
 char firstletterlast = lastname[0];
 char fifthdigitid = id[4];
 char sixthdigitid = id[5];
 string idcode = firstletterfirst, firstletterlast, fifthdigitid, sixthdigitid ;
 return idcode;


double mean(int v[], int size)
// PRE: size of array > 0
// POST: return average of values in array

 int sum = 0;
 for (int i = 1; i <= size; i++)
 
 sum = sum + v[i - 1];
 
 double mean = sum / size;
 return mean;


double stddev(int v[], int size, double m)

 double sumofsquares = 0;
 double spread[25];
 double var;
 double stddev;
 for (int i = 1; i < size; i++)
 
 spread[i - 1] = (v[i - 1] - m)*(v[i - 1] - m);
 sumofsquares = sumofsquares + spread[i - 1];
 
 var = sumofsquares / 25;
 stddev = sqrt(var);
 return stddev;


char letter(int score, double m, double s)
// PRE: 0 <= score, m, s <= 100
// POST: return letter grade for score with mean m and standard deviation s

 char grade;
 if (score < (m - (1.5 * s)))
 grade = 'E';
 else if (score >= (m - (1.5 * s)) && score < (m - (0.5*s)))
 grade = 'D';
 else if (score >= (m - s) && score < m)
 grade = 'C';
 else if (score >= (m+(0.5*s)) && score < (m + 1.5*s))
 grade = 'B';
 else
 grade = 'A';
 return grade;