array-vs-dict.swift

import Foundation

var sum = 0
for count in [10, 20, 30, 40, 50, 60, 70, 80, 90, 100] {
    print("Benchmarking for \(count) elements")
    
    let randomKeys = Array(0..<count).shuffled()

    let readKeysCount = count * 100
    var randomReadKeys = [Int]()
    for _ in 0..<readKeysCount {
        randomReadKeys.append(randomKeys.randomElement()!)
    }

    let loopRuns = 100_000_000

    let array = randomKeys.map({ ($0, Bool.random()) })
    let dictionary = Dictionary<Int, Bool>(uniqueKeysWithValues: array)
    


    var start = Date()
    for i in 0..<loopRuns {
        let key = randomReadKeys[i % readKeysCount]
        let element = array.first(where: { $0.0 == key })!.1
        sum &+= element ? 1 : 0
    }
    print("Array took \(Date().timeIntervalSince(start))")

    start = Date()
    for i in 0..<loopRuns {
        let key = randomReadKeys[i % readKeysCount]
        let element = dictionary[key]!
        sum &+= element ? 1 : 0
    }
    print("Dictionary took \(Date().timeIntervalSince(start))")
    print("\n===================\n")
}

print(sum)