Program eating a first letter of a line - c++

Question

So I'm practicing working with files in C++ a bit. I've created a simple program that loads Student's name, index number, date of birth and grades from STUDENT.txt, counts the student's average, and writes it all down in a form below to a different file.
It all works like a charm, except one thing: It eats up the first letter of every line. EXAMPLE:
I have a STUDENT.txt file that looks like this:
Alice Cooper
225883
21/6/1986
6,6,8,9,10
Zakk Wylde
27568
14/5/1978
6,6,6,6,6
So the first student, Cooper, will be processed correctly, but everyone else in the file won't. They'll be written down as 'akk Wylde'...
So everything but a name is OK.
I was hoping someone could tell me what exactly is going on, I'm guessing it's eating up a '\n' and another character, but I couldn't find it with debugging.
// Student_datoteka.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
std::string toString(int day, int month, int year) {
std::string d, m, g, ret;
d = std::to_string(day);
m = std::to_string(month);
g = std::to_string(year);
ret += d;
ret += "/";
ret += m;
ret += "/";
ret += g;
return ret;
}
int main()
{
std::fstream load("STUDENTI.txt", std::ios::in);
std::ofstream write("IZVJESTAJ.txt");
write << std::setw(30) << std::left << "Student"
<< std::setw(10) << "Indeks"
<< std::setw(20) << "Datum rodjenja"
<< std::setw(10) << "Prosjek" << std::endl;
write << std::setw(30) << std::left << "-------"
<< std::setw(10) << "------"
<< std::setw(20) << "--------------"
<< std::setw(10) << "-------" << std::endl;
if (!write)
std::cout << "ERROR!";
std::string name;
int indeks(0), day(0), month(0), year(0);
char sign(0), sign2(0);
int grades[30];
double average(0);
while (std::getline(load, name)) {
if (load.eof()) break;
load >> indeks;
load >> day >> sign >> mjesec >> sign2 >> year;
int i(0);
while (load >> grades[i]) {
load >> sign;
average += grades[i];
i++;
}
average /= double(i);
std::string datum = toString(day, month, year);
write << std::setw(30) << std::left << name
<< std::setw(10) << indeks
<< std::setw(20) << datum
<< std::setw(10) << std::setprecision(2)
<< average<< std::endl;
average = 0;
if (load.eof()) break;
load.clear();
}
return 0;
}
This is the output: http://prntscr.com/jvm3jn

Answer 1

I have made a small improvements on your code so please, if you don't like, take only the working part. Note that my code can be improved and generalized even more but I am leaving that to you.
Hope you would like my solution:
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <iomanip>
typedef struct Student
{
std::string name;
int index_no;
int day_of_birth;
int month_of_birth;
int year_of_birth;
std::vector<int> grades;
double avg_grade;
} Student;
std::string date_to_string(int day, int month, int year)
{
std::string d, m, g, ret;
d = std::to_string(day);
m = std::to_string(month);
g = std::to_string(year);
ret += d;
ret += "/";
ret += m;
ret += "/";
ret += g;
return ret;
}
void get_date_from_str(int& day, int& month, int& year, std::string const& str)
{
std::stringstream ss(str);
ss >> day;
ss.ignore(1);
ss >> month;
ss.ignore(1);
ss >> year;
}
void get_numbers_from_str(std::vector<int>& vec, std::string const& str)
{
std::stringstream ss(str);
int i;
while (ss >> i)
{
vec.push_back(i);
ss.ignore(1);
}
}
double calculate_avg(std::vector<int> const& vec)
{
int sum = 0;
for (auto item : vec)
{
sum += item;
}
return (double) sum / vec.size();
}
int main()
{
std::ifstream students_file("students.txt");
std::ofstream report_file("report.txt");
if (students_file.is_open() && report_file.is_open())
{
report_file << std::setw(30) << std::left << "Student"
<< std::setw(10) << "Indeks"
<< std::setw(20) << "Datum rodjenja"
<< std::setw(10) << "Prosjek" << std::endl;
report_file << std::setw(30) << std::left << "-------"
<< std::setw(10) << "------"
<< std::setw(20) << "--------------"
<< std::setw(10) << "-------" << std::endl;
std::vector<Student> students;
std::string name;
while (std::getline(students_file, name))
{
std::string index_no;
std::string date_of_birth;
std::string grades;
Student student;
student.name = name;
std::getline(students_file, index_no);
std::stringstream(index_no) >> student.index_no;
std::getline(students_file, date_of_birth);
std::getline(students_file, grades);
get_date_from_str(student.day_of_birth, student.month_of_birth, student.year_of_birth, date_of_birth);
get_numbers_from_str(student.grades, grades);
student.avg_grade = calculate_avg(student.grades);
students.push_back(student);
}
for (auto student : students)
{
report_file << std::setw(30) << std::left << student.name
<< std::setw(10) << student.index_no
<< std::setw(20) << date_to_string(student.day_of_birth, student.month_of_birth, student.year_of_birth)
<< std::setw(10) << std::setprecision(2)
<< student.avg_grade << std::endl;
}
}
else
{
std::cout << "Unable to open one of the files!" << std::endl;
}
return 0;
}
First, I think you have complicated your code for both, reading and understanding it, while you have some C++ features that can simplify this part with signs and parsing date and grades.
I have also created struct Student and I have split some of the code into functions.
And, regarding your solution. As someone already mentioned in the comment, fault is in these lines:
while (load >> grades[i])
{
load >> sign;
average += grades[i];
i++;
}
You are 'eating' one character more than you need. And this character is the first character of the name of the second student. Therefore, if you change your code to following, you'll see what I'm talking about:
while (load >> grades[i])
{
if (i != 4) // just a temporary solution, since the first student has 5 grades
load >> sign;
average += grades[i];
i++;
}