Question

Calculate probability of true positive true negative false positive false negative in bloom filterc

Answer 1

Bloom Filter is a Probabilistic data structure,that is used to test the existence of an element in a set. If ‘x’ is the element and ‘S’ is the set,the existence of the element ‘x’ in set ’S’ returns 1(true),else will return 0(false).

A Bloom Filter consists of a vector array of n boolean values,initially all set to 0(false), as well as ‘k’ independent hash functions, h0,h1,….h(k-1) each within range of {0,1,2,….,n-1}. An element can be added into the bloom filter but not deleted from it, when an element ‘x’ has to be added to it,the element is hashed with ‘k’ hash functions and ‘n’ array positions are obtained,and the value in those indexes are changed to 1. so when we want to search the existence of the element it is hashed with it hash functions and checked if the values at their array positions are 1 and if the value is 1(true) at all its array positions, the existence of element is returned 1(true).