hi there i was wondering if any1 could help me with this problem. i am a beginner at c++ and my coursework is asking me to create a program with a hash function and i am lost! could any1 tell me how to implement this? here is my problem -

Write your own hash function* that uses the 6 digit grid reference as a key. Using this function and the hill details already generated, add the hill details to another array, this time of 63 elements. This will be your hash table.Test that a user can search the hash table by asking the user to enter a grid reference. The program should either output details of the hill at that grid reference or output that there is no hill at that grid reference.

here is my code-

#include <iostream>
using namespace std;

struct Node{		//a structure that can be 
	int data;		//thought of as a simple class
	Node *link;		//All fields are public
	int height;
	int gridReference;
	int distance;
	bool climbed;
};

class LinkedList{
public:
	Node *head;		//pointer to the first node
	Node *last;		//pointer to the last node
	int count;		//number of nodes

	LinkedList();	//default constructor 
					//first = NULL
					//last = NULL
					//count = 0
	
	~LinkedList();	//destructor - deletes all nodes
					//from the linked list 
	
	void insertFirstNode(int newinfo); // inserts a node
							//at the start of the list
	void insertLastNode(int newinfo);  // inserts a node
							//at the end of the list
	void insertHills(int height, int distance, bool climbed, int gridReference);

	int getNodeCount();  //returns the number of nodes
	Node* getFirst();	 //returns the pointer to the 
						 //the first node - the value of "head"
	void displayData();
};



#include "linkedlist.h"


LinkedList::LinkedList(){
	head = NULL;
	last = NULL;
	count = 0;
}

LinkedList::~LinkedList(){
	Node *temp = head->link;
	while(temp) {
		head->link = temp->link;
		delete temp;
		temp = head->link;
	}
	delete head;
	cout<<"linked list deleted"<<endl;
}

void LinkedList::insertFirstNode(int newInfo){
	Node *newNode;
	newNode = new Node;
	newNode->data = newInfo;
	newNode->link = head; 
	head = newNode;

	count++;

	if(last == NULL){
		last = newNode;
	}
}

void LinkedList::insertLastNode(int newInfo){
	Node *newNode;
	newNode = new Node;
	newNode->data = newInfo;
	newNode->link = NULL; 


	count++;

	if(head == NULL){
		head = newNode;
		last = newNode;
	}
	else{
		last->link = newNode;
		last = newNode;
	}
}

int LinkedList::getNodeCount(){
	return count;
}

Node* LinkedList::getFirst(){
	return head;
}

void LinkedList::insertHills(int height, int distance, bool climbed, int gridReference){

	Node* current= head;
	Node* previous= NULL;
	Node* hills= new Node();
	count++;

	hills->height= height;
	hills->distance= distance;
	hills->climbed= climbed;
	hills->gridReference= gridReference;
	hills->link= NULL;

	if(count==1)
	{          
		head= hills;
		last= hills;
		return;
	}
	do{
		if(current->height<hills->height)
		{
			hills->link= current;

			if(current== head)
			{
				head= hills;
				return;
			}
			else
			{
				previous->link= hills;
				return;
			}
			if(current==last)
			{
				current->link=hills;
				last= hills;
				return;
			}
		}
		previous=current;
		current= current->link;

	}          
	while(current!=NULL);
}


void LinkedList::displayData(){
	int noOfNodes= getNodeCount();
	Node *current;
	current= head;


	cout << "Number of Nodes = " << noOfNodes << endl;
	for(int i=0; i<noOfNodes && current != NULL; i++){
		cout<<"Hill Number: "<<count--<<endl;

		cout<<"Height: "<<current->height<<endl;

		cout<<"Distance from Home: "<<current->distance<<endl;

		cout<<"Climbed: "<<current->climbed<<endl;

		cout<<"Grid Reference: "<<current->gridReference<<endl;

		cout<<"**************"<<endl;
		current= current->link;


	}
}


#include <cstdlib>
#include <iostream>
#include "linkedlist.h"







int main(){
	LinkedList l;


	for(int i=1; i<41; i++){

		int randHeight= (rand()%1400)+3000;// generates random number for height of hill

		int randDistance= (rand()%280)+20;// generates random number for distance of hill

		int randGridReference= (rand()%100000)+400000;// generates random number for gridreference of hill

		int randClimbedNumber= (rand()%10)+1;// generates random number to tell user if hill is climbed

		bool randClimbed;
		if(randClimbedNumber>5)//This takes the random number generated from randClimbedNumber and determines if it has been climbed or not
		{
			randClimbed= true;
		}
		else
		{
			randClimbed= false;
		}
		l.insertHills(randHeight, randDistance, randClimbed, randGridReference);
	}     

	l.displayData();

	cout<<endl;


	l.displayData();


	return 0;
}

THANKS!!

>could any1 tell me how to implement this?
Use this hash function until you get the rest of your hash table working:

unsigned hash ( int )
{
  return 0;
}

Hi there I am sorry i don't understand. i have tried looking up simple ways of implementing hash tables but i can't find any. i habe no idea where to start with them

Well, that's different then. Your question strongly suggested that you were having trouble writing a hash function, not a hash table. I'll suggest this tutorial, and this one as well.

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