Binary Search Output Issue in Inventory Program c++ - c++

Question

I am having issues with binary search function within my homework (I am completely done with it except for this one issue).
The program allows a user to manage the inventory of a small store that sells various products of any type. It will first read the inventory from a text file named “inventory.dat”, reading the product name, sku, quantity, and price. It will contain up to 100 products.
Then, it should offer the user a menu with the following options:
Display the inventory sorted by sku. (displayInventory function)
Lookup a product by sku. (lookupSku function)
Lookup a product by name. (lookupname function)
Quit
The program should perform the selected operation and then re-display the menu.
When I select option 2 and enter a sku number, my program outputs a random item's information instead of the one that was typed in by the user.
Here is my code starting in the main function along with the lookupBySku function:
int main()
{
// Initialize variables & array
int userInput;
//max array size
const int MAX_SIZE = 100; //const to make it constantly be 100
//declare and open input file
ifstream fin;
fin.open("inventory.dat");
//declare strings to hold data
string productName, sku, quantity, price;
if (!fin) // checking if file was inputted correctly or not.
{
cout << "File not found! Try again. " << endl;
return 1;
}
Inventory items[MAX_SIZE];
Inventory temp[MAX_SIZE];
cout << left << setw(20) << "Product Name " <<
left << setw(10) << "sku #" <<
left << setw(3) << "Quantity " <<
left << setw(0) << " Price\n";
//declare number of objects in inventory
int numOfObjects = 0;
while(!fin.eof())
{
getline(fin, productName);
getline(fin, sku);
getline(fin, quantity);
getline(fin, price);
if(productName == "")
{
break;
}
items[numOfObjects].name = productName;
cout << left << setw(20) << items[numOfObjects].name;
items[numOfObjects].sku = sku;
cout << left << setw(10) << items[numOfObjects].sku;
items[numOfObjects].quantity = quantity;
cout << left << setw(4) << items[numOfObjects].quantity;
items[numOfObjects].price = price;
cout << left << setw(0) <<"\t\t" << items[numOfObjects].price << endl;
++numOfObjects;
}
//check to see if there are more than 100 items
if(numOfObjects > 100)
{
cout << "File is too large, terminating program...\n";
return -1;
}
// Constants for menu choices
const int DISPLAY_BY_SKU = 1,
LOOKUP_BY_SKU = 2,
LOOKUP_BY_NAME = 3,
QUIT_CHOICE = 4;
do
{
// Set up numeric output formatting.
cout << fixed << showpoint << setprecision(2);
cout << "Manage Inventory Menu\n" <<endl;
cout << "1. Display inventory sorted by sku. " <<
"\n2. Lookup a product by sku. " <<
"\n3. Lookup a product by name. " <<
"\n4. Quit the program\n" << endl;
cout << "Enter your choice : ";
cin >> userInput;
cout << endl;
while (userInput < DISPLAY_BY_SKU || userInput > QUIT_CHOICE)
{
cout << "Please enter a valid menu choice: ";
cin >> userInput;
}
switch(userInput)
{
case DISPLAY_BY_SKU:
{
displayInventory(items, numOfObjects);
break;
}
case LOOKUP_BY_SKU:
{
lookupSku(items, numOfObjects);
break;
}
case LOOKUP_BY_NAME:
{
lookupName(items, numOfObjects);
break;
}
case 4:
cout << "Exiting the program." <<endl;
break;
}
}
while (userInput != QUIT_CHOICE);
fin.close();
return 0; }
void lookupSku (Inventory items[], int numOfObjects) {
string number;
int first = 0;
int last = numOfObjects - 1;
int middle;
int position = -1;
bool found = false;
cout << "Enter the sku that you'd like to search for : ";
cin >> number;
cout << endl;
while(!found && first <= last)
{
middle = (first + last)/2;
if(items[middle].sku == number)
{
found = true;
position = middle;
}
else if(items[middle].sku > number)
{
last = middle - 1;
}
else if(items[middle].sku < number)
{
first = middle + 1;
}
}
cout << "Your item is shown below : \n" << endl
<< "Product Name : "<< items[middle].name << endl
<< " Sku : " << items[middle].sku << endl
<<" Quantity : " << items[middle].quantity << endl
<< " Price : " << items[middle].price << endl
<< endl;
}