Develop An Algorithm To Search And Remove Data From A Hash T

Develop An Algorithm To Search And Remove Data From a Hash Table Using

Develop an algorithm to search and remove data from a hash table using the open addressing technique. Implement a hash table using open addressing with linear probing. You need to complete the following methods in the OpenAddrHashTable.java class:

  • public void put(K key, V value)
  • private int searchPosition(K key)
  • public void remove(K key)
  • public Optional get(K key)

Study the pseudocode shown in Snippets 3.3 and 3.4 and implement them in Java. The container class OpenAddrPair should hold your key and value with a flag indicating when an item is deleted. Use this flag in the put operation to overwrite a deleted slot. This flag also helps optimize the get method via filtering.

The pseudocode for inserting using linear probing (Snippet 3.3) involves calculating the hash value, probing sequentially, and inserting at the first available slot. The pseudocode for searching (Snippet 3.4) similarly uses linear probing to locate the key, stopping when it finds null or the matching key.

Paper For Above instruction

Hash tables are fundamental data structures that offer efficient data retrieval and storage capabilities, especially when handling large datasets. Among various collision resolution techniques, open addressing with linear probing is a popular method due to its simplicity and effective load management when the hash table maintains a low load factor. This paper discusses implementing an open addressing hash table in Java, emphasizing the methods for inserting, searching, and removing data, following a pseudocode-based approach.

To facilitate this, the OpenAddrHashTable class needs to implement four essential methods: put, searchPosition, remove, and get. The put method is responsible for inserting data into the hash table. It uses the searchPosition helper method to locate the correct index to insert or overwrite data, considering previously deleted slots. Open addressing requires linear probing, where upon collision, the algorithm probes sequentially until an empty or deleted slot is found. When inserting, if a deleted slot is encountered, it can be reused for the new data, optimizing space utilization.

The searchPosition method implements the core logic of probing to find the position of a given key in the hash table. It must handle wrap-around using modular arithmetic and stop when it either finds the key, hits an empty slot, or traverses the entire table. Proper handling of the deleted flag in OpenAddrPair entries enables efficient lookups with the get method, which searches with the same probing logic and filters out entries marked as deleted.

The remove method marks an existing entry as deleted rather than removing it entirely, which helps maintain the integrity of the probing sequence for other keys. Marking an entry as deleted rather than nullifying it preserves the probing chain, ensuring that lookups for other keys that collided continue to work correctly.

Implementing these methods requires measuring the load factor, handling edge cases like full tables, and ensuring thread safety if concurrent access is considered. The pseudocode provides a blueprint to follow, emphasizing the importance of modular arithmetic for index calculation, probe sequencing, and proper flag management for deletions and insertions. Together, these strategies build a robust open addressing hash table that efficiently manages data insertions, searches, and deletions in Java.

References

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