Implementation of Hash Table with chaining

In my last post about hash table I have explained how hash table with chaining works. Now let's try to implement that.

First thing we'll do is - create a class called HashTable.

In this class at first we'll declare a private variable called HASH_MAX that will be the size of hash table. Next we'll create a class called linkedList, it works same as the Node class we made in the linked list implementation. And after this will declare the hashTable array that is linkedList type.

Now will declare the constructor and functions we need. First function is the hash function that we've talked about in last post. Next we'll declare the insertItem() function through which we'll insert our hash table values. And the last two functions are numberOfItemsInIndex() that returns size of every index and printTable() will print the values of the hash table.

Now let's see in details how these constructors and functions work.

HashTable():

In this constructor we're just putting default values to every index of the hashTable. First we are creating a new linkedList and assigning it in hashTable's every index, then we are giving a default data to the linked list of that index and giving default value to the next pointer.

hashFunction(string key):

This is the same hashFunction we used in the last post. we're just adding up all the ASCII values of the string and returning sum mod HASH_MAX.

insertItem(string key):

For insertion first we'll pass the string through the hashFucntion and initialize the returned value in the index variable. Then we'll check if any value is saved in that index or not. If the data element of the first element is equal to  "empty"(that is out default value) then there is no value saved in this index, so we'll just initialize the data of the first element of that list as the string we provided. But if there is one or more values saved in that linked list, then we'll create a pointer called tmp and initialize it with hashTable[index] linkedList and then create a new node for this linked list called x and will initialize data of this node with the provided string and the next pointer of this node with NULL. After that we'll run a loop till end of the list and when we'll go to the last element, we'll just initialize it's next pointer with the new node (i.,e x) we created.

numberOfItemInIndex(int index):

Thais fuction takes a index number as parameter and returns how many strings are saved in that linked list. First we check if the list is empty of not, if it is empty we'll return 0 else we'll increase the count then declare a linkedList type poiter called tmp and initialize it with linkedList of the provided index. Then we'll just run loop till end of the list and increase the count variable and then return the value.

printTable():

This function is pretty self explanatory. We've just print the size and elements of the linked list of every index. I've already explained  linked list print before you can see that.
Full Source Code