Question

The c++ program is supposed to store the txt into a stack depending on the what the random number generator assigns each student and stores them into the stack. But it keeps giving me the same outputs and I can't figure out why?

#include<iostream>
#include<fstream>
#include<string>
#include<sstream>
#include<stack>
using namespace std;

struct student {
int ID;
string last_name;
double gpa;
};

void read_std_file(student* std);
void store_std_into_stack(stack <student> ss, student std[]);
void wite_output_file(student std);

void read_std_file(student* std)
{
ifstream file;
file.open("C://temp//students.txt");
if (file.fail())
{
cout << "\nFile opening error!!";
exit(1);
}
string line;
int counter = 0;
int index = 0;
while (getline(file, line))
{
stringstream ss(line);
string token;
counter = 0;
while (getline(ss, token, ','))
{
if (counter == 0)
std[index].ID = stoi(token);
else if (counter == 1)
std[index].last_name = token;
else if (counter == 2)
std[index].gpa = stod(token);
counter++;
}
index++;
}
file.close();
}

void store_std_into_stack(stack <student> ss, student std[])
{
int rand_num = 0;
char choice;
for (int i = 0; i < 10; i++)
{
rand_num = rand() % 20 +1;
if (rand_num % 2 == 0)
ss.push(std[i]);
if (rand_num % 2 != 0)
if (rand_num % 3 == 0)
{

cout << "\nPress Y to see stack and N for quit ";
cin >> choice;
if (choice == 'y')
{
if (!ss.empty())
{
cout << "\nNumber of students on stack: " << ss.size() << endl;
cout << "ID\t\t" << "last name\t\t" << "GPA" << endl;
for (int i = 0; i <= ss.size(); i++)
{
student s = ss.top();
cout << s.ID << "\t\t" << s.last_name << "\t\t" << s.gpa << endl;
ss.pop();
}
}
cout << endl << endl;
exit(0);
}
}
else
{
if (!ss.empty())
{
wite_output_file(ss.top());
ss.pop();
}
}
}
}

void wite_output_file(student std)
{
ofstream file;
file.open("C://temp//output.txt");
if (file.fail())
{
cout << "\nError Opening output file to write!!";
exit(1);
}
file << std.ID << "," << std.last_name << "," << std.gpa << "\n";
file.close();
}

//main driver function
int main()
{
//array for 10 students
student std[10];
//stack to store student data from array
stack <student> ss;

//calling function to read student data from student.txt file
//and store it in std array
read_std_file(std);

//calling function to store data from array to stack
store_std_into_stack(ss, std);

cout << endl << endl;
}

Answer 1

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <stack>
#include <ctime>
#include <cstdlib>

using namespace std;

struct student {
   int ID;
   string last_name;
   double gpa;
};

void read_std_file(student* std);
void store_std_into_stack(stack <student> ss, student std[]);
void wite_output_file(student std);

void read_std_file(student* std)
{
   ifstream file;
   file.open("C://temp//students.txt");
   if (file.fail())
   {
       cout << "\nFile opening error!!";
       exit(1);
   }
   string line;
   int counter = 0;
   int index = 0;
   while (getline(file, line))
   {
       stringstream ss(line);
       string token;
       counter = 0;
       while (getline(ss, token, ','))
       {
           if (counter == 0)
               std[index].ID = stoi(token);
           else if (counter == 1)
               std[index].last_name = token;
           else if (counter == 2)
               std[index].gpa = stod(token);
           counter++;
       }
       index++;
   }
   file.close();
}

void store_std_into_stack(stack <student> ss, student std[])
{
   int rand_num = 0;
   char choice;
   for (int i = 0; i < 10; i++)
   {
       rand_num = rand() % 20 +1;
       if (rand_num % 2 == 0)
           ss.push(std[i]);
       if (rand_num % 2 != 0)
           if (rand_num % 3 == 0)
           {
               cout << "\nPress Y to see stack and N for quit ";
               cin >> choice;
               if (choice == 'y')
               {
                   if (!ss.empty())
                   {
                       cout << "\nNumber of students on stack: " << ss.size() << endl;
                       cout << "ID\t\t" << "last name\t\t" << "GPA" << endl;
                       for (int i = 0; i <= ss.size(); i++)
                       {
                           student s = ss.top();
                           cout << s.ID << "\t\t" << s.last_name << "\t\t" << s.gpa << endl;
                           ss.pop();
                       }
                   }  
                   cout << endl << endl;
                   exit(0);
               }
           }
           else
           {
               if (!ss.empty())
               {
                   wite_output_file(ss.top());
                   ss.pop();
               }
           }
   }
}

void wite_output_file(student std)
{
   ofstream file;
   file.open("C://temp//output.txt");
   if (file.fail())
   {
       cout << "\nError Opening output file to write!!";
       exit(1);
   }
   file << std.ID << "," << std.last_name << "," << std.gpa << "\n";
   file.close();
}

//main driver function
int main()
{
   // seed the random number generator with current time value, so that every time the program runs a different sequence of integers are generated
   // without this statement, the random number generator will generate the same sequence of integers every time the program is run
   srand(time(0));
  
   //array for 10 students
   student std[10];
   //stack to store student data from array
   stack <student> ss;

   //calling function to read student data from student.txt file
   //and store it in std array
   read_std_file(std);

   //calling function to store data from array to stack
   store_std_into_stack(ss, std);

   cout << endl << endl;
}