Help with a linked list problem

[ralversity]

(I originally posted this in the beginner forum section but I think it should have been posted here instead after reading the rules more not completely sure though.)

Hello Everyone,

I have a project due for a class and I'm not asking for direct answers but I'm asking for whatever help I can get and coding examples would be appreciated or something to point me in the right direction. This project is over linked lists and dynamic arrays in C++. The part I am stuck on is creating a function to organize "packages" I was given two structs:
// Package_Node struct to create a list of packages
struct Package_Node
{
int bar_code;
float package_weight;
struct Package_Node *next_package;
};

// Key_Node struct to store key information for dynamic array of keys
struct Key_Node
{
int key = 0;
struct Package_Node *next_package;
};

The Key_Node struct is supposed to be used to create a dynamic array based off a user input for a number of keys. I'm supposed to generate the barcodes by doing a random number between 1 and Max Value. The package weights are calculated as a random float between 1 and 500. I'm supposed to organize the packages barcode and weight by placing them in the key generated from barcode % X.

The way it's supposed to look is like this:
Array of keys is created and for example looks like this
0
1
2

Then once I run organize packages, let's say the user entered 4 for X keys. Once the packages are made and done they get placed into the according keys and the table is supposed to look like this when I print all the information:
0 -> 4 - 32.0
1 -> 15 - 405.5
2 -> 14 - 44.5 -> 18 - 200.0

I should note that I was told my ArrayOfKeys function is correct for what I need so I mainly just need to figure out the other part.

I hope this is enough information to give you guys an idea of what I'm looking for. I'm really stuck on this and even though I kind of know how to do some basic linked lists I'm really struggling on how to implement a method to insert things into the specific keys and how it all links together.

If you need more information or anything let me know, I hope I gave enough of what was needed. Thank you for any help I can get, I'd like to improve since right now I'm definitely not very good at this.

The Issues I am having are at the bottom of my code. I wasn't sure how much to take out or leave in so sorry if it's long :(.

#include "stdafx.h" // Visual studio
#include <iostream> // NULL, cin, cout etc.
#include <time.h> // time
#include <stdlib.h> // srand, rand
#include <array> // arrays
using namespace std;

// Package_Node struct to create a list of packages
struct Package_Node
{
	int bar_code;
	float package_weight;
	struct Package_Node *next_package;
};

// Key_Node struct to store key information for dynamic array of keys
struct Key_Node
{
	int key = 0;
	struct Package_Node *next_package;
};
//Defines Nodeptr to Package_Node for use to make the linked list
typedef Package_Node* Nodeptr;

//All my functions so far, haven't created the comments to describe each of these but I don't think that'd be an issue
// for the feedback
void menu(int N, int Max_Value, int X, Key_Node *Key_Array, Nodeptr package_info);

void NumOfKeys(int &X, int &Max_Value);

void NumOfPackages(int &N);

void ArrayOfKeys(Key_Node *Key_Array, int X);

void OrganizePackages(Nodeptr package_info, int Max_Value, int X, int N, Key_Node *Key_Array);

void InsertList(Nodeptr& head, Nodeptr& tail, Nodeptr package_info);


int main()
{
	//Initializing variables
	// Total number of packages to create
	int N = 0;
	// Max value for bar codes generated
	int Max_Value = 0;
	//Number of keys for array
	int X = 0;
	//arrayPos to keep track of array index for keys
	Key_Node *Key_Array = nullptr;
	// code and weight to assign values to bar_code and package_weight for Package_Node
	Nodeptr package_info = nullptr;
	menu(N, Max_Value, X, Key_Array, package_info);
	return 0;
}


void menu(int N, int Max_Value, int X, Key_Node *Key_Array, Nodeptr package_info)
{
	// Menu loop to continue loop unless user enters 7
	bool menuLoop = true;
	do
	{
		// base menu
		cout << "What would you like to do?\n";
		cout << "1) Enter number of keys and the Max Value\n";
		cout << "2) Enter number of packages (N)\n";
		cout << "3) Create Array of Keys\n";
		cout << "4) Organize Packages (organizes the N packages)\n";
		cout << "5) Table stats\n";
		cout << "6) Clean table\n";
		cout << "7) Exit\n";

		// User input for choice from menu for use in switch statement
		int choice;
		cin >> choice;

		switch (choice)
		{

			case 1:
			{
				NumOfKeys(X, Max_Value);
				break;
			}

			case 2:
			{
				NumOfPackages(N);
				break;
			}

			case 3:
			{
				ArrayOfKeys(Key_Array, X);
				break;
			}

			case 4:
			{
				// Checks if no keys or number of packages have been entered yet and goes back to menu if not
				if (X == 0 || N == 0)
				{
					cout << "No keys and/or number of packages were entered.\n";
					break;
				}
				else
				{
					OrganizePackages(package_info, Max_Value, X, N, Key_Array);
				}
				break;
			}

			case 5:
			{
				// Extra menu for table choices with another switch statement for user choice
				int tableChoice;
				cout << "What would you like to do with the table?\n";
				cout << "0) Find packages given a bar code\n";
				cout << "1) Total number of objects given a key\n";
				cout << "2) Total weight given a key\n";
				cout << "3) Print List given a key\n";
				cout << "4) Print Entire Table\n";
				cout << "5) Find all package that are greater than a given weight\n";
				cin >> tableChoice;
				switch (tableChoice)
				{
					case 0:
					{
						TableFindPackage();
						break;
					}

					case 1:
					{
						TableTotalNumOfObjects();
						break;
					}

					case 2:
					{
						TableTotalWeight();
						break;
					}

					case 3:
					{
						TablePrintList();
						break;
					}

					case 4:
					{
						TablePrintTable();
						break;
					}

					case 5:
					{
						TableFindGreaterWeight();
						break;
					}

				}
			}

			case 6:
			{
				CleanTable();
				break;
			}

			case 7:
			{
				// Stops loop because user chose to exit
				menuLoop = false;
				break;
			}
		}
	} while (menuLoop == true);
}


void NumOfKeys(int &X, int &Max_Value)
{
	// Asks user for number of keys
	cout << "Please enter the number of keys that will be used: ";
	cin >> X;

	// Asks user for Max Value of barcode
	cout << "\nPlease Enter the Max Value of the barcode: ";
	cin >> Max_Value;
	cout << "\n";
}

void NumOfPackages(int &N)
{
	// Asks user for number of packages
	cout << "Please enter the number of packages (N): ";
	cin >> N;
	// Goes back to menu after user enters information
}

void ArrayOfKeys(Key_Node *Key_Array, int X)
{
	Key_Array = new Key_Node[X];

	// Displays the values in the array created and initializes them to 0, 1 , 2 etc. until user entered key is reached
	cout << "Your array now has the values: \n";
	for (int i = 0; i < X; i++)
	{
		Key_Array->key = i;
		Key_Array->next_package = NULL;
		cout << Key_Array->key << " \n";
	}
}

//** Part where issue starts
void OrganizePackages(Nodeptr package_info, int Max_Value, int X, int N, Key_Node *Key_Array)
{
	// Min value for bar code
	int Min_Value = 1;
	// float values for weight

	//Initializes head and tail to NULL (Not sure if tail is necessary yet)
	Nodeptr head = NULL, tail = NULL;
	//Initialize random seed
	srand(static_cast<unsigned int>(time(NULL)));

	if (package_info->next_package == NULL)
	{
		package_info = new Package_Node;
		// Generate random number between Min_Value and Max_Value for barcode
		package_info->bar_code = rand() % Max_Value + Min_Value;

		// Generate random float weight for package of 1 - 500
		package_info->package_weight = static_cast <float> (rand() % 500 + 1);

		// Places package with information into key
		Key_Array->key = (package_info->bar_code % X);

		// Inserts information into list
		InsertList(head, tail, package_info);
	}

}

//**This is wrong and causes a crash
void InsertList(Nodeptr& head, Nodeptr& tail, Nodeptr package_info)
{
	Nodeptr NewPtr = NULL, tempPtr = NULL;
	while (NewPtr = package_info)
	{
		//Add object to the list
		if (head == NULL)
		{
			//beginning of the list
			head = NewPtr;

			// Current record
			tail = NewPtr;
		}
		else
		{
			//Previous record reference to new record
			{
				tail->next_package = NewPtr;
				// Current Record
				tail = NewPtr;
			}
		}
		// End of the list
		tail->next_package = NULL;

		for (tempPtr = head; tempPtr != NULL; tempPtr = tempPtr->next_package)
		{
			cout << "\n" << (tempPtr->bar_code) << "-" << (tempPtr->package_weight) << "\n";
		}
	}
}

[dhayden]

The Key_Node struct is supposed to be used to create a dynamic array based off a user input for a number of keys.

Key_Node is supposed to be an array, but you have it as a list. It needs to be an array of pointers to Package_Node. Ideally you'd use std::vector for this. If you have to code it yourself then Key_Node should be:

struct Key_Node {
    int size;
    struct Package_Node **packages;
};

The function prototypes change to:

//All my functions so far, haven't created the comments to describe each of the\
se but I don't think that'd be an issue
// for the feedback
void menu(int N, int Max_Value, Key_Node &Key_Array);

void NumOfKeys(int &X, int &Max_Value);

void NumOfPackages(int &N);

void ArrayOfKeys(Key_Node &Key_Array, int X);

void OrganizePackages(int Max_Value, int N,
                      Key_Node &Key_Array);

void InsertList(Nodeptr &head, Nodeptr package_info);

ArrayOfKeys just allocates the array:

void
ArrayOfKeys(Key_Node &Key_Array, int X)
{
    Key_Array.packages = new Package_Node*[X];
    Key_Array.size = X;

    cout << "Your array now has the values: \n";
    for (int i = 0; i < X; i++) {
        Key_Array.packages[i] = NULL;
        cout << i << '\n';
    }
}

And OrganizePackages looks like this. Note how I've used package_info->bar_code % Key_Array.size to select which list to insert it in.

//** Part where issue starts
void
OrganizePackages(int Max_Value, int N, Key_Node &Key_Array)
{
    // Min value for bar code
    int Min_Value = 1;
    // float values for weight

    //Initialize random seed
    srand(static_cast < unsigned int >(time(NULL)));

    for (int i=0; i<N; ++i) {
        Nodeptr package_info = new Package_Node;
        // Generate random number between Min_Value and Max_Value for barcode
        package_info->bar_code = rand() % Max_Value + Min_Value;

        // Generate random float weight for package of 1 - 500
        package_info->package_weight = static_cast < float >(rand() % 500 + 1);

        // Places package with information into key
        InsertList(Key_Array.packages[package_info->bar_code % Key_Array.size],
                   package_info);
    }

}

And finally, InsertList becomes ridiculously easy, especially since I'm not keeping a tail pointer.

void
InsertList(Nodeptr & head, Nodeptr package_info)
{
    package_info->next_package = head;
    head = package_info->next_package;
}

[ralversity]

Maybe I'm missing something here but when I try to display the table with this nothing comes up? This did help me with figuring some things out though I'm just wondering how I would display this information along with the keys like I wrote in the original post because it doesn't seem like the information is stored for that.

What I'm referring to is displaying it like this in the console:
(key)0 -> 4 - 32.0
(key)1 -> 15 - 405.5
(key)2 -> 14 - 44.5 -> 18 - 200.0