How do I implement a bloom filter in Swift?

This article provides an implementation of a Bloom Filter in Swift, a space-efficient probabilistic data structure used to test whether an element is a member of a set.

Bloom Filter, Swift, Data Structures, Probabilistic Data Structure, Membership Testing


        // Swift implementation of a Bloom Filter
        
        import Foundation
        
        class BloomFilter {
            private var bitArray: [Bool]
            private let size: Int
            private let hashFunctions: [(String) -> Int]
        
            init(size: Int, hashFunctions: [(String) -> Int]) {
                self.size = size
                self.bitArray = Array(repeating: false, count: size)
                self.hashFunctions = hashFunctions
            }
        
            func add(_ element: String) {
                for hashFunc in hashFunctions {
                    let index = hashFunc(element) % size
                    bitArray[index] = true
                }
            }
        
            func contains(_ element: String) -> Bool {
                for hashFunc in hashFunctions {
                    let index = hashFunc(element) % size
                    if !bitArray[index] {
                        return false
                    }
                }
                return true
            }
        }
        
        // Example hash functions
        func simpleHash(_ input: String) -> Int {
            return input.reduce(0) { $0 + Int($1.asciiValue ?? 0) }
        }
        
        func alternativeHash(_ input: String) -> Int {
            return input.reduce(1) { $0 * Int($1.asciiValue ?? 0) }
        }
        
        // Usage
        let bloomFilter = BloomFilter(size: 1000, hashFunctions: [simpleHash, alternativeHash])
        bloomFilter.add("example@example.com")
        print(bloomFilter.contains("example@example.com"))  // true
        print(bloomFilter.contains("test@test.com"))        // false (probabilistically)

How do I implement a bloom filter in Swift?

Popular Topics

Recent Languages

How do I implement a bloom filter in Swift?

Related Questions

Popular Topics

Recent Languages