SwiftAlgorithms.swift

import UIKit

// MAKING CHANGE ---------------------------------------------
func makingChange (amount: Int, denominations: [Int]) -> Int {
    var waysOfDoingNCents: [Int] = []
    for _ in 0...amount {
        waysOfDoingNCents.append(0)
    }
    waysOfDoingNCents[0] = 1
    
    for coin in denominations {
        for higherAmount in coin...amount {
            let remainder = higherAmount - coin
            waysOfDoingNCents[higherAmount] = waysOfDoingNCents[remainder]
        }
    }
    
    return waysOfDoingNCents[amount]
}
// makingChange(amount: 5, denominations: [1, 3, 5])

// FIZZBUZZ ---------------------------------------------

func fizzBuzz (quantity: Int) {
    for index in 1...quantity {
        if index % 3 == 0 && index % 5 == 0 {
            print("Fizz Buzz")
        } else if index % 3 == 0 {
            print("Fizz")
        } else if index % 5 == 0 {
            print("Buzz")
        } else {
            print(index)
        }
    }
}
// fizzBuzz(quantity: 20)

func fizzBuzzAlternative (quantity: Int) {
    for index in 1...quantity {
        var result = ""
        
        if index % 3 == 0 {
            result += "Fizz"
        }
        
        if index % 5 == 0 {
            result += (result.isEmpty ? "" : " ") + "Buzz"
        }
        
        if result.isEmpty {
            result += "\(index)"
        }
        
        print(result)
    }
}

// fizzBuzzAlternative(quantity: 20)

// QUICKSORT ---------------------------------------------
func quickSort<T: Comparable>(array: [T]) -> [T] {
    guard array.count > 1 else { return array }
    
    let pivot = array[array.count / 2]
    
    let lesser = array.filter { $0 < pivot }
    let equal = array.filter { $0 == pivot }
    let greater = array.filter { $0 > pivot }
    
    return quickSort(array: lesser) + equal + quickSort(array: greater)
}

// quickSort(array: [1, 5, 52, 5, 123, 754, 12, 4, 2, 676, 123, 5, 1234])


// REVERSE STRING IN PLACE ---------------------------------------------

func reverseStringInPlace (_ string: String) -> String {
    var strArray: [String] = []
    
    for char in string.characters {
        strArray.insert(String(char), at: 0)
    }
    
    return strArray.joined()
}

func reverseStringInPlace (_ string: inout String) {
    var strArray: [String] = []
    
    for char in string.characters {
        strArray.insert(String(char), at: 0)
    }
    
    string = strArray.joined()
}

//var string = "Hello, world"
//reverseStringInPlace(&string)
// reverseStringInPlace("Hello, World")