chriswebb09

struct HashTable<Key: Hashable, Value> {
  // Hash table setup 
  func index(for key: Key) -> Int {
        var divisor: Int = 0
        for key in String(describing: key).unicodeScalars {
            divisor += abs(Int(key.value.hashValue))
        }
        return abs(divisor) % buckets.count
    }
}

chriswebb09

struct HashTable<Key: Hashable, Value> {
    
    typealias Bucket = [HashElement<Key, Value>]
    
    var buckets: [Bucket]
    
    init(capacity: Int) {
        assert(capacity > 0)
        buckets = Array<Bucket>(repeatElement([], count: capacity))
    }

chriswebb09

class HashElement<T: Hashable, U> {
    var key: T
    var value: U?
    
    init(key: T, value: U?) {
        self.key = key
        self.value = value
    }
}

chriswebb09

struct Stack<T> {
    
    var isEmpty: Bool {
        return items.isEmpty
    }
    
    var count: Int {
        return items.count
    }
    

chriswebb09

struct Queue<T> {
    
    var list = LinkedList<T>()
    
    mutating func enqueue(_ element: T) {
        list.append(value: element)
    }
    
    mutating func dequeue() -> T? {
        guard !list.isEmpty, let element = list.first else { return nil }

chriswebb09

import UIKit

class PlaylistItem {
    var track: iTrack?
    var next: PlaylistItem?
    weak var previous: PlaylistItem?
}

extension PlaylistItem: Equatable {
    static func ==(lhs: PlaylistItem, rhs: PlaylistItem) -> Bool {

chriswebb09

class LinkedList<T> {
    
    public typealias Node = LLNode<T>
    
    private var head: Node?
    private var tail: Node?
    
    var isEmpty: Bool {
        return head == nil
    }

chriswebb09

class LLNode<T> {
    
    var value: T
    var next: LLNode?
    weak var previous: LLNode?
    
    init(value: T) {
        self.value = value
    }
}

chriswebb09

import UIKit

class PlaylistItem {
    var track: iTrack?
    var next: PlaylistItem?
    weak var previous: PlaylistItem?
}

extension PlaylistItem: Equatable {
    static func ==(lhs: PlaylistItem, rhs: PlaylistItem) -> Bool {

chriswebb09

import UIKit

class Playlist {
    
    private var head: PlaylistItem?
    
    var itemCount: Int = 0
    
    var isEmpty: Bool? {
        return head == nil