ChenCodes

//iterative
func binarySearch<T: Comparable>(_ a: [T], key: T) -> Int? {
    var lowerBound = 0
    var upperBound = a.count
    while lowerBound < upperBound {
        let midIndex = lowerBound + (upperBound - lowerBound) / 2
        if a[midIndex] == key {
            return midIndex
        } else if a[midIndex] < key {
            lowerBound = midIndex + 1

ChenCodes

public class BinarySearchTree<T: Comparable> {
  private(set) public var value: T
  private(set) public var parent: BinarySearchTree?
  private(set) public var left: BinarySearchTree?
  private(set) public var right: BinarySearchTree?

  public init(value: T) {
    self.value = value
  }

ChenCodes

var randomNumbers = [5, 4, 3, 2, 1]

func selectionSort(nums: inout [Int]) -> [Int] {
    
    // index of element we're trying to put in the leftmost position
    for i in 0..<nums.count - 1 {
        
        // set our smallest element to be the current index's element 
        var smallestElement = nums[i]
        // set our smallest index to be the current index's element 

ChenCodes

func bubbleSort(nums: inout [Int]) -> [Int] {
    
    while true {
        var swapped = false
        
        for i in 0..<nums.count - 1 {
            if nums[i] > nums[i + 1] {
                let temp = nums[i]
                nums[i] = nums[i + 1]
                nums[i + 1] = temp

ChenCodes

// Without threading
func slow() {
  let methodStart = Date()
  let url = URL(string: "some string url goes here for an image")
  
  do {
    let data = try Data(contentsOf: url!)
    self.imageView.image = UIImage(data: data)
  } catch {
    print("error"

ChenCodes

var noParametersOrReturn: () -> () = {
  print("I have no parameters or return values, so I print"
}

// noParametersOrReturn()

var noParameterAndOneReturn: () -> String = {
    return "I am a string"
}