Searching Algorithms Questions Medium
Linear probing is a technique used in hashing to resolve collisions that occur when two or more keys are mapped to the same index in a hash table. It is a simple and straightforward method that involves sequentially searching for the next available slot in the hash table when a collision occurs.
When a collision happens, instead of storing the key-value pair directly at the hashed index, linear probing checks the next consecutive index in the table. If that index is empty, the key-value pair is inserted there. If the next index is already occupied, the probing continues to the next index until an empty slot is found.
To search for a key using linear probing, the hash function is applied to the key to determine the initial index. If the key is not found at that index, the algorithm sequentially checks the next indices until either the key is found or an empty slot is encountered.
Linear probing has both advantages and disadvantages. One advantage is that it provides a simple and efficient way to handle collisions, as the search for an empty slot is done in a linear manner. It also allows for a high load factor, meaning the hash table can be filled to a large extent before performance starts to degrade.
However, linear probing can suffer from clustering, where consecutive occupied slots create long runs of filled indices. This can lead to decreased performance as the number of collisions increases, resulting in longer search times. Additionally, linear probing may cause poor cache performance due to its sequential nature.
In summary, linear probing is a collision resolution technique in hashing that sequentially searches for the next available slot in the hash table when a collision occurs. While it is a simple and efficient method, it can suffer from clustering and potential cache performance issues.