Imagine for different key values same block of the hash table is allocated now where do they previously store values corresponding to some other previous key go. This picture stops being so rosy and perfect when the concept of a hash collision is introduced. So whenever we need to fetch a value corresponding to a key, that is just O(1). So the process is simple, the user gives a (key, value) pair set as input, and based on the value generated by the hash function an index is generated to where the value corresponding to the particular key is stored. The entire process ensures that for any key, we get an integer position within the size of the Hash Table to insert the corresponding value. So modulo operator is a compressor in our implementation.
We will use the hash code generated by JVM in our hash function and compress the hash code we modulo(%) the hash code by the size of the hash table. In Java, every object has its own hash code. Hash code is an Integer number (random or non-random). Every hash function has two parts a Hash code and a Compressor. Now the entire process is described belowĮvery time a key is generated. In a Hash Table, instead of an index, we use a key to fetch the value corresponding to that key. Now as we observe in an array to fetch a value we provide the position/index corresponding to the value in that array. Interestingly every key is unique in a Hash Table but values can repeat which means values can be the same for different keys present in it. Find the smallest window in a string containing all characters of another stringĮvery hash-table store data in the form of a (key, value) combination.Return maximum occurring character in an input string.Given an array A and a number x, check for pair in A with sum as x.Using underscore in Numeric Literals in Java.Currying Functions in Java with Examples.Using _ (underscore) as variable name in Java.Implementing our Own Hash Table with Separate Chaining in Java.Differences between HashMap and HashTable in Java.Differences between TreeMap, HashMap and LinkedHashMap in Java.Comparator Interface in Java with Examples.Collections.sort() in Java with Examples.ISRO CS Syllabus for Scientist/Engineer Exam.ISRO CS Original Papers and Official Keys.