Your task is to go through and implement the methods getBucketIndex, add, get, and remove. Follow the comments inside respective methods.

import java.util.ArrayList;

import java.util.Scanner;

public class HashtableChaining $\{$

$//$ Hashtable bucket

private ArrayList$>$ bucket;

$//$ Current capacity of the array list

private int numBuckets;

$//$ current size of the array list

private int size;

public HashtableChaining$($int buckets$)\{$

bucket $=$ new ArrayList$<>()$;

numBuckets $=$ buckets;

size $=0$;

$//$ create empty chains

for$($int i $=0$; i $<$ numBuckets; i$++)\{$

bucket.add$($null$)$;

$\}$

$\}$

public int size$()\{$

return size;

$\}$

public boolean isEmpty$()\{$

return size$()==0$;

$\}$

private int getBucketIndex$($K key$)\{$

$//$ Implement Multiplicative hash

$//$ Assume INITIAL$\_$VALUE $=7$ HASH$\_$MULTIPLIER $=3$

$\}$

$//$Adds a key value pair to hash

public void add$($K key, V value$)\{$

$//$ Find head of chain for given key

$//$ Check if key is already present

$//$ Insert key in chain

$//$ If load factor goes beyond threshold $(0\mathrm{.}75),$ then double the hash size

$//$ and rehash the existing items

$//$ print "Doubling the size, load factor $>0\mathrm{.}75"$ when you double the hash size.

$\}$

$//$ Returns value for a key

public V get$($K key$)\{$

$//$ Find head of chain for given key

$//$ Search key in chain

$//$ If key not found return null

return null;

$\}$

$//$ Removes key from the hashtable

public V remove$($K key$)\{$

$//$ Apply hash function to find index for a given key

$//$ get head of the chain

$//$ Search for key in its chain

$//$ If key is found

$//$ Reduce size

$//$ Remove key and return

$//$ Else keep moving in the chain

$//$If key was not there return null

return null;

$\}$

public static void main$($String$[]$ args$)\{$

Scanner input $=$ new Scanner$($System$.$in$)$;

System.out.println$("$Enter the initial capacity:"$)$;

int size $=$ input.nextInt$()$;

HashtableChaining hashtable $=$ new HashtableChaining$<>($size$)$;

System.out.println$("$Adding items to hashtable:"$)$;

hashtable.add$("$FALL$2017",3)$;

hashtable.add$("$SPRING$2018",3)$;

hashtable.add$("$SUMMER$2018",1)$;

hashtable.add$("$FALL$2018",4)$;

hashtable.add$("$SPRING$2019",2)$;

hashtable.add$("$SPRING$2019",3)$;

System.out.printf$("$Size of the hashtable is $\%$d$\%$n$",$ hashtable.size$())$;

System.out.println$("$Removing key SUMMER$2018")$;

System.out.printf$("$The value is $\%$d$\%$n$",$ hashtable.remove$("$SUMMER$2018"))$;

System.out.printf$("$Now the size of the hashtable is $\%$d$\%$n$",$

hashtable.size$())$;

System.out.println$("$Looking up key SUMMER$2018")$;

System.out.printf$("$The value is $\%$s$\%$n$",$

hashtable.get$("$SUMMER$2018"))$;

System.out.printf$("$Is the hashtable empty? :$\%$s$\%$n$",$

hashtable.isEmpty$()?$ "True" : "False"$)$;

input.close$()$;

$\}$

$\}$