Question

please use Java!!
We are storing the inventory for our fruit stand in a hash table. The attached file shows all the possible key/fruit combinations that can be inserted into your hash table. These are the real price lookup values for the corresponding fruit. Problem Description In this programming assignment, you will implement a hash table class fruitHash. Your hash table must include the following methods: 1) hashFunction(key) This method takes a key as an argument and returns the address (i.e. index in hash table), of the data to be stored. You will need to implement two hash functions: hash with linear probing, and double hashing. Namely, linearHash(key) and doubleHash(key). Recall that linear probing simply checks for the next available space in the table, and returns the memory address (i.e. index in hash table). Recall that double hashing using two hash functions. 2) insert(key,data) First, this insert method invokes linearHash(key) or doubbleHash(key) to find index in hash table. Second, put data into the space referenced by the found index. 3) find(key) The find method accepted the key as an argument, and returns the data.

Answer 1

class Fruit{
    private String fruitName;
    private int key;
    private boolean isDeleted;
  
    public Fruit(){
      
    }
  
    public Fruit(String name, int k, boolean isDel){
        fruitName = name;
        isDeleted = isDel;
        key = k;
    }
  
    public String getFruitName(){
        return fruitName;
    }
    public int getKey(){
        return key;
    }
    public boolean isDeleted(){
        return isDeleted;
    }
    public void setFruitName(String name){
        fruitName = name;
    }
    public void setKey(int k){
        key = k;
    }
    public void setDeleted(boolean b){
        isDeleted = b;
    }
}

class fruitHash{
    private Fruit[] fruitTable;
    private int tableSize;
  
    public fruitHash(int size){
        fruitTable = new Fruit[size];
        tableSize = size;
        for(int i = 0; i < tableSize; i++)
            fruitTable[i] = null;
    }
  
    public int size(){
        return tableSize;
    }
  
    public void insert(int key, String data){
        int k = hashFunction(key);
        if(fruitTable[k] != null){
            int k2 = doubleHash(key);
            if(fruitTable[k2] != null){
                int k3 = linearHash(key);
                if(k3 == -1){
                    System.out.println("Error: Table is full, cannot insert '"+data+"'");
                    return;
                }
                fruitTable[k3] = new Fruit(data, key, false);
            }else{
                fruitTable[k2] = new Fruit(data, key, false);
            }
        }else{
            fruitTable[k] = new Fruit(data, key, false);
        }
    }
  
  
    String find(int key){
        int k = hashFunction(key);
        if(fruitTable[k] == null){
            int k2 = doubleHash(key);
            if(fruitTable[k2] == null){
                int k3 = linearHash(key);
                if(k3 == -1){
                    return null;
                }
                if(fruitTable[k3].isDeleted())
                    return null;
                if (fruitTable[k3].getKey() == key) {
                    return fruitTable[k3].getFruitName();
                }
                return null;
            }else{
                if(fruitTable[k2].isDeleted())
                    return null;
                if (fruitTable[k2].getKey() == key) {
                    return fruitTable[k2].getFruitName();
                }
                return null;
            }
        }else{
            if(fruitTable[k].isDeleted())
                return null;
            if (fruitTable[k].getKey() == key) {
                return fruitTable[k].getFruitName();
            }
            return null;
        }
    }
  
    public void rehash(){
        tableSize *= 2;
        Fruit[] newtable = new Fruit[tableSize];
        for(int i = 0; i < tableSize; i++)
            newtable[i] = null;
        for(int i = 0; i < tableSize/2; i++){
            if(fruitTable[i] != null && !fruitTable[i].isDeleted()){
                int key = fruitTable[i].getKey();
                int k = hashFunction(key);
                if (newtable[k] != null) {
                    int k2 = doubleHash(key);
                    if (newtable[k2] != null) {
                        int k3 = linearHash(key);
                        if (k3 == -1) {
                            System.out.println("Error: Table is full!");
                            return;
                        }
                        newtable[k3] = new Fruit(fruitTable[i].getFruitName(), key, false);
                    } else {
                        newtable[k2] = new Fruit(fruitTable[i].getFruitName(), key, false);
                    }
                } else {
                    newtable[k] = new Fruit(fruitTable[i].getFruitName(), key, false);
                }
            }
        }
        fruitTable = newtable;
    }
  
    public void printTable(){
        System.out.println("FruitTable:");
        for(int i = 0; i < tableSize; i++){
            if(fruitTable[i] != null && !fruitTable[i].isDeleted()){
                System.out.println(" key: " + fruitTable[i].getKey() + ", value: " + fruitTable[i].getFruitName());
            }
        }
    }
  
    public void delete(int key){
        int k = hashFunction(key);
        if(fruitTable[k] == null){
            int k2 = doubleHash(key);
            if(fruitTable[k2] == null){
                int k3 = linearHash(key);
                if(k3 > 0){
                    fruitTable[k3].setDeleted(true);
                }
            }else{
                fruitTable[k2].setDeleted(true);
            }
        }else{
            fruitTable[k].setDeleted(true);
        }
    }
  
    private int hashFunction(int key){
        return key % tableSize;
    }
    private int linearHash(int key){
        int k = key % tableSize;
        int index = k;
        while(index < tableSize){
            if(fruitTable[index] == null)
                return index;
            if(fruitTable[index] != null && fruitTable[index].isDeleted())
                return index;
            index++;
        }
        index = 0;
        while(index < k){
            if(fruitTable[index] == null)
                return index;
            if(fruitTable[index] != null && fruitTable[index].isDeleted())
                return index;
            index++;
        }
        return -1;
    }
    private int doubleHash(int key){
        int k = key % tableSize;
        int k2 = 7 - (key % 7);
        int k2temp = k2, index = k;
        while(k2temp > 0){
            index++;
            if(index >= tableSize)
                index = 0;
            k2temp--;
        }
        return index;
    }
}

public class FruitTable {

    public static void main(String[] args) {
        fruitHash fhash = new fruitHash(10);
        System.out.println("Table size: "+fhash.size());
        fhash.insert(4514, "alfafa sprouts");
        fhash.insert(4131, "apple fuji");
        fhash.insert(4133, "apple gala");
        fhash.insert(4017, "apple granny smith");
        fhash.insert(4218, "apricots");
        fhash.insert(4525, "asparagus");
        fhash.insert(4225, "avocado large hass");
        fhash.insert(4227, "avocado small");
        fhash.insert(4234, "banana leaf");
        fhash.insert(4011, "banana");
        fhash.insert(4232, "banana baby");
        fhash.insert(4229, "banana burro");
        fhash.insert(4235, "banana macho");
        fhash.insert(4885, "basil");
        fhash.insert(4536, "bean sprouts");
        fhash.insert(3176, "beans black");
        fhash.insert(3196, "beans back eye");
        fhash.insert(3174, "beans garbanzo");
        fhash.insert(4066, "beans green");
        fhash.insert(3175, "beans haba dry");
        fhash.printTable();
        System.out.println("Find 4131: "+fhash.find(4131));
        System.out.println("Find 4011: "+fhash.find(4011));
        System.out.println("Find 4525: "+fhash.find(4525));
    }
  
}

Output - Fruit Table (run) x run: Table size: 10 Error: Table is full, cannot insert 'banana baby' Error: Table is full, cannot insert 'banana burro Error: Table is full, cannot insert 'banana macho Error: Table is full, cannot insert 'basil Error: Table is full, cannot insert 'bean sprouts Error: Table is full, cannot insert 'beans black' Error: Table is full, cannot insert 'beans back eye' Error: Table is full, cannot insert 'beans garbanzo' Error: Table is full, cannot insert 'beans green' Error: Table is full, cannot insert 'beans haba dry' FruitTable: key: 4234, value: banana leaf key: 4131, value: apple fuji key: 4011, value: banana key: 4133, value: apple gala key: 4514, value: alfafa sprouts key: 4525, value: asparagus key: 4225, value: avocado large hass key: 4017, value: apple granny smith key: 4218, value: apricots key: 4227, value: avocado small Find 4131: apple fuji Find 4011: null Find 4525: asparagus