Vector Problem Debug assertion failed line779

[Tripic]

ok the error says debug assertion failed vector subscript out of range line 779. Im nw to trying to use vectors so this is probably a simple and stupid question but it compiled with no problem but breaks as soon as i run the Clist function. Any help and maybe a bit of guidance where i went wrong with the vector would be
appreciated .

#include <iostream>
#include <fstream>
#include <string>
#include <stdlib.h>
#include <vector>
using namespace std;
ifstream fIn;
ofstream fOut;
int menu();
void Clist ();
int menuOpt;

int main()
{
menu();
}
int menu()
{
char inp;

do
{
cout << "Please chose from the following options" <<endl;
cout << "A: Load Trivia type." <<endl;
cout << "B: Start Game." <<endl;
cout << "C: Exit Game" <<endl;
cin >> inp;
string bt;	

switch(inp)
{
case 'a':	
	Clist();	
	break;
case 'b': 
	cout << "test2" << endl;
	break;
case 'c':
	return 0;
	break;
case 'A':
	Clist();
	break;
case 'B': 
	cout << "test2" << endl;
	break;
case 'C':
	return 0;
	break;
default:
	cout << "error that is not an option\n Press enter to continue " << endl;
	cin.get();
	cin.get();
	system("cls");
	break;
}}while(inp != 'c');
}



void Clist()
{	
	vector<string> triviaName;
	vector<string> fileName;
	int a, b, c;
	fIn.open("list.csv");
  
	while(!fIn.eof())
	{
	a = 1;
	getline( fIn, triviaName[a], ',' );
	getline( fIn, fileName[a]);
	a++;
		}
	for(b = 1; b < a; b++)
	{
		c = 1;
		cout << triviaName[c] << " || " << fileName[c] << endl;
		c++;
	}

	fIn.close();	
  cin.get();
  cin.get();
  system("cls");

}

[kevinchkin]

Line 779 O.O? Where is it?

while(!fIn.eof())
	{
	a = 1;
	getline( fIn, triviaName[a], ',' );
	getline( fIn, fileName[a]);
	a++;
		}

In this code, you are assigning a = 1 at the beginning of the loop? Other thing is vectors start from 0 and you are directly accessing it's first element in

getline( fIn, triviaName[a], ',' );
	getline( fIn, fileName[a]); 

It should be from 0.

Hope this helps !

[helios]

std::vectors don't grow automatically.
Use std::vector::resize() to... well, resize it, and std::vector::push_back() to add an element to the back of the vector.
Also note that vectors, like arrays, use zero-based indexing, so the first element is 0, the second is 1, and so on. But don't let this confuse you into passing 0 to resize(). That will make the vector of size 0; it won't make element 0 the last element of the vector.