answersLogoWhite

0

ANSWER A hash table is a way to find data in an array, when you have a known key and an unknown value that corresponds to the key. You use a hashing function on the key to create an index into the hash table containing the value. In the ideal case, this directly returns the corresponding value. In the usual case, a collision can occur. This means that the hashed key points to multiple possible values. A hash table is usually used on large arrays that would take a long time to search using other methods. A hash table can be very fast and use very little memory, and does not require the array to be sorted. The source code is slightly more complicated than some search methods. With a poorly designed hashing function when the hashed keys do not correspond one-to-one with the values, the secondary search after a hash collision can take a large amount of time.

User Avatar

Wiki User

16y ago

What else can I help you with?

Continue Learning about Engineering

What is hash key?

hash key is an element in the hash table. it is the data that you will combine (mathematical) with hash function to produce the hash.


C plus plus program to implement quadratic probing?

Quadratic probing is a collision resolution technique used in hash tables. In C++, you can implement it by defining a hash table class and a hash function, then using a quadratic formula to calculate the next index when a collision occurs. The formula typically used is (hash + i^2) % table_size, where i is the number of attempts. Here's a simple implementation outline: #include <iostream> #include <vector> class QuadraticProbingHashTable { std::vector<int> table; int size; public: QuadraticProbingHashTable(int s) : size(s), table(s, -1) {} void insert(int key) { int index = key % size; int i = 0; while (table[index] != -1) { index = (index + i * i) % size; // Quadratic probing i++; } table[index] = key; } void display() { for (int i = 0; i < size; i++) std::cout << i << ": " << table[i] << std::endl; } }; This code snippet initializes a hash table, inserts keys using quadratic probing, and displays the table's contents.


What are the methods of hash table?

See the related link below for the Java API documentation for the Hashtable class and its methods.


What difference does it make if you remove a period in a hash?

It makes a big difference because if you compared the hash: abcde.fg = hash 1 to abcdefg = hash 3 The results hash 1 and hash 3 are not equal.


What is hash queue?

A hash queue is a data structure that combines the properties of both a hash table and a queue. It allows for efficient insertion, deletion, and retrieval of elements while maintaining a specific order. This structure ensures that elements can be accessed in constant time on average, while also enabling the management of items in a first-in, first-out (FIFO) manner. Hash queues are useful in scenarios where quick access and ordered processing of items are both required.

Related Questions

What is the major advantage of a hash table?

The major advantage of a hash table is its speed. Because the hash function is to take a range of key values and transform them into index values in such a way that the key values are distributed randomly across all the indices of a hash table.


What is hash key?

hash key is an element in the hash table. it is the data that you will combine (mathematical) with hash function to produce the hash.


What is hash table in sql?

temp table


What is the optimal hash table size for achieving efficient performance when dealing with prime numbers?

The optimal hash table size for efficient performance when dealing with prime numbers is typically a prime number that is close to but not exceeding the desired capacity of the hash table. This helps reduce collisions and ensures a more even distribution of values across the table, leading to better performance.


What are the causes of bucket overflow in a hash file organization?

Bucket overflow in a hash file organization occurs when multiple keys hash to the same bucket, exceeding its capacity. This can happen due to a poor hash function that generates many collisions, insufficient bucket size, or an uneven distribution of keys. Additionally, if the dataset grows significantly without adjusting the hash table size, it can lead to frequent overflows. Effective strategies like resizing the hash table or using chaining can help mitigate this issue.


Insert value into hash table?

Insertion in hash tables is based on a 'key' value which is calculated on the basis of a hash function. This hash function generates the key based on what type of data it is fed. For example hash function for an integer input might look like this : int hash(int val) { return (val%101); } where return value of hash function would become a key. Complete implementation can be found at: http://simplestcodings.blogspot.com/2010/07/hash-table.html


What is the advantage of table?

One advantage of decision table is that table is drawn in the first iteration which acts as a stepping stone to derive a new decision table. One disadvantage is that the table does not scale up well.


Define hashing and describe briefly including types of hashing and where it is used and advantages and disadvantages of hashing?

Hashing is performed on arbitrary data by a hash function. A hash function is any function that can convert data to either a number or an alphanumeric code. There are possibly as many types of hashing as there are data. How precisely the hash function works depends on what data it is meant to generate a hash code from. Hashing is used for a variety of things. For example, a hash table is a data structure used for storing data in memory. Instead of iterating through the structure to find a specific item, we associate a key (hash code) to a particular item (data). A hash code can be generated from a file or disk image. If the data does not match the code, then the data is assumed to be corrupted. Hashing has the advantage of taking a larger amount of data and representing it as a smaller amount of data (hash code). The code generated is unique to the data it came from. Generating a hash code can take time however, depending on the function and the data. Some hash functions include Bernstein hash, Fowler-Noll-Vo hash, Jenkins hash, MurmurHash, Pearson hashing and Zobrist hashing.


C plus plus program to implement quadratic probing?

Quadratic probing is a collision resolution technique used in hash tables. In C++, you can implement it by defining a hash table class and a hash function, then using a quadratic formula to calculate the next index when a collision occurs. The formula typically used is (hash + i^2) % table_size, where i is the number of attempts. Here's a simple implementation outline: #include <iostream> #include <vector> class QuadraticProbingHashTable { std::vector<int> table; int size; public: QuadraticProbingHashTable(int s) : size(s), table(s, -1) {} void insert(int key) { int index = key % size; int i = 0; while (table[index] != -1) { index = (index + i * i) % size; // Quadratic probing i++; } table[index] = key; } void display() { for (int i = 0; i < size; i++) std::cout << i << ": " << table[i] << std::endl; } }; This code snippet initializes a hash table, inserts keys using quadratic probing, and displays the table's contents.


What is the advantage of a frequency table?

none


What is The advantage data in a table?

organisational


What are the methods of hash table?

See the related link below for the Java API documentation for the Hashtable class and its methods.