Something

#include <iostream>
#include <fstream>
using namespace std;

struct items {
	
	char itemID[7];
	char description[31];
	float minbid;
};

struct seller {
	
	char sellername[12];
	char sellerID[3];
};

char itoa (int data);
void charcat (char* data, char cat);

int main()
{

	items itemsData;
	seller sellerData;
	char id[3];
	char answer;


	fstream binary;
	binary.open("seller_list.dat", ios::in | ios::binary);


	do
	{
	cout << "What is the sellers id?";
	cin >> id;

	binary.read(reinterpret_cast<char *>(&sellerData), sizeof(sellerData));

	int index = 0;
	bool found = false;
	int total = 0;

	while (index < 17 && !found)
	{
		binary.read(reinterpret_cast<char *>(&sellerData), sizeof(sellerData));
		if (strcmp(id, sellerData.sellerID) == 0)
		{
			found = true;
			cout << sellerData.sellerID;
			cout << "How many items are you selling? ";
			cin >> total;
				for(int i = 0; i < total; i++)
				{
					strcpy(itemsData.itemID, sellerData.sellerID);
				        strcat(itemsData.itemID, "00");
					charcat(itemsData.itemID, itoa(i + 1));

					cout << "What is a description for that item? ";
					cin >> itemsData.description;
					cout << "What is the minimum bid? ";
					cin >> itemsData.minbid;
				}
		}
		index++;
	}
	cout << "Do you want to enter for another seller(y/n)? ";
	cin >> answer;

	} while (answer == 'Y' || answer == 'y');



}


char itoa (int data) 
{

    char i = (char)(0x30 + data);
    return i;

}

void charcat (char* data, char cat) 
{

    int i = strlen(data);
    data[i] = cat;
    data[i + 1] = '\0';

}