please do the get , put , and rehash methods. r Linear Probing Hash Table public

Question

please do the get, put, and rehash methods.

r Linear Probing Hash Table public class Hashtable private int currentsize, max Size public Pair map null stores hash table elements Constructor public Hashtable capacity) currentSize 0; maxsize capacity map new Pa for Cinti 0; i maxSize i++) map Cil null Function to check if hash table is empty public boolean is EmptyO return getSize 0; Function to get size of hash table public int getsize return currentsize; Function to check if hash table is full o public boolean isFullO return currentsize max Size

Explanation / Answer

Hashtable.java

public class Hashtable {
   private int currentSize, maxSize;
   public Pair[] map=null;
  
   //Cunstructor
   public Hashtable(int capacity){
       currentSize=0;
       maxSize= capacity;
       map=new Pair[maxSize];
       for(int i=0;i<maxSize;i++)
           map[i]=null;
   }
  
   //Function to check if hash table is empty
   public boolean isEmpty(){
       return getSize()==0;
   }

   //Function to get size of the hash table
   public int getSize() {
       return currentSize;
   }
  
   //Function to check if hash table is full
   public boolean isFull(){
       return currentSize==maxSize;
   }
  
   //Function to check if hastable contains a key
   public boolean contains(String key){
       return get(key)!=null;
   }
  
   //Function to get hash-code/hash value for a given key
   public int hash(String key){
       return Math.abs(key.hashCode())%maxSize;
   }
  
   //Function to get value for a given key
   public String get(String key){
       //Get element value using key and linear probing if the element doesnot exist return null
       for (Pair pair : map) {
           if(pair.getKey().equals(key))
               return pair.getValue();
       }
       return null;
   }
  
   //Functon to insert key-value pair
   public void put(String key, String val){
       //insert element val using key, If the table is full you must call rehash first
       Pair pair=new Pair(key,val);
       if(isFull())
           rehash();
       map[currentSize]=pair;
       currentSize++;
      
      
   }
  
   //Function to rehash when the table is full
   private void rehash(){
       //backup the reference to the old table
       Pair[] map1=map;
       //create new map twice the size of the old size
       map=new Pair[currentSize*2];
       maxSize=currentSize*2;
      
       //hash all the elements from the old hash to new hash map
       for (int i=0;i<currentSize;i++) {
           map[i]=map1[i];
       }
   }
  
   //Function to print HashTable
   public void printHashTable(){
       System.out.println(" Hash Table: Key, Value ");
       for(int i=0;i<maxSize;i++){
           if(map[i]!=null)
               System.out.println(map[i].getKey()+", "+map[i].getValue());
       }
       System.out.println();
   }
}

Pair.java

public class Pair {
   private String key;
   private String value;
  
   public Pair(String key, String value){
       this.key=key;
       this.value=value;
   }

   public String getKey() {
       return key;
   }

   public void setKey(String key) {
       this.key = key;
   }

   public String getValue() {
       return value;
   }

   public void setValue(String value) {
       this.value = value;
   }

}

HashTest.java

public class HashTest {

   public static void main(String[] args) {
       Hashtable myTable=new Hashtable(2);
       System.out.println("Is table Empty "+myTable.isEmpty());
       myTable.put("Key_1", "Value_1");
       myTable.put("Key_2", "Value_2");
       System.out.println("Get value of Key_2: "+myTable.get("Key_2"));
       System.out.println(" Is table Empty: "+myTable.isEmpty());
       System.out.println("Size of the table: "+myTable.getSize());
       myTable.printHashTable();
       myTable.put("Key_3","Value_3");
       myTable.put("Key_4", "Vlaue_4");
       System.out.println("Get value of Key_2: "+myTable.get("Key_2"));
       System.out.println("Size of the table: "+myTable.getSize());
       myTable.printHashTable();
   }

}

Sample Output:

Is table Empty true
Get value of Key_2: Value_2

Is table Empty: false
Size of the table: 2

Hash Table:
Key, Value
Key_1, Value_1
Key_2, Value_2

Get value of Key_2: Value_2
Size of the table: 4

Hash Table:
Key, Value
Key_1, Value_1
Key_2, Value_2
Key_3, Value_3
Key_4, Vlaue_4

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.