bradleyyin

- (NSString *)ageOnDifferentPlanet:(double)seconds {
    double earthYears = seconds / 31557600.0;
    double mercuryYears = earthYears / 0.2408467;
    double venusYears = earthYears / 0.61519726;
    double marsYears = earthYears / 1.8808158;
    double jupiterYears = earthYears / 11.862615;
    double saturnYears = earthYears / 29.447498;
    double uranusYears = earthYears / 84.016846;
    double neptuneYears = earthYears / 164.79132;
    

bradleyyin

import Foundation

func makeChangeAsString(fromAmount: Double, withCost: Double) -> String {
    guard fromAmount >= withCost else { return "Invalid change"}
    let change = fromAmount - withCost
    var changeInCent = Int(change * 100)
    let dollar = changeInCent / 100
    changeInCent -= dollar * 100
    let quarter = changeInCent / 25
    changeInCent -= quarter * 25

bradleyyin

import Foundation

func makeChangeAsString(fromAmount: Double, withCost: Double) -> String {
    guard fromAmount >= withCost else { return "Invalid change"}
    let change = fromAmount - withCost
    var changeInCent = Int(change * 100)
    let dollar = changeInCent / 100
    changeInCent -= dollar * 100
    let quarter = changeInCent / 25
    changeInCent -= quarter * 25

bradleyyin

import Foundation

func sameNumberOfBinaryOnes(_ number: Int) -> (Int, Int?) {
    let stringNumInBinary = "\(number, radix: .binary)"
    var numOfOneInNum: Int = 0
    for element in stringNumInBinary {
        if element == "1" {
            numOfOneInNum += 1
        }

bradleyyin

import Foundation

func doAsTheRomansDoAndNumeralize(_ number: Int) -> String {
    guard number > 0 else { return "" }
    var romanNumeral = ""
    
    let mRemainder = romanize(number: number, romanNumeral: &romanNumeral, value: 1000, romanSymbol: "M")
    let cmRemainder = romanize(number: mRemainder, romanNumeral: &romanNumeral, value: 900, romanSymbol: "CM")
    let dRemainder = romanize(number: cmRemainder, romanNumeral: &romanNumeral, value: 500, romanSymbol: "D")
    let cdRemainder = romanize(number: dRemainder, romanNumeral: &romanNumeral, value: 400, romanSymbol: "CD")

bradleyyin

func bubbleSort(_ numbers: [Int]) -> [Int] {
    var numbers = numbers
    var clean = false
    while !clean {
        clean = true
        for i in 0...(numbers.count - 2)  {
            if numbers[i] > numbers[i + 1] {
                let tempNum = numbers[i]
                numbers[i] = numbers[i + 1]
                numbers[i + 1] = tempNum

bradleyyin

//"Challenge 9: Find pangrams
//Difficulty: Tricky
//
//Write a function that returns true if it is given a string that is an English pangram, ignoring letter case.
//
//Tip: A pangram is a string that contains every letter of the alphabet at least once.
//
//Sample input and output
//The string "The quick brown fox jumps over the lazy dog" should return true.
//The string "The quick brown fox jumped over the lazy dog" should return false, because it's missing the S.

bradleyyin

"Challenge 8: String is rotated
Difficulty: Tricky

Write a function that accepts two strings, and returns true if one string is rotation of the other, taking letter case into account.

Tip: A string rotation is when you take a string, remove some letters from its end, then append them to the front. For example, "swift" rotated by two characters would be "ftswi".

Sample input and output
The string "abcde" and "eabcd" should return true.
The string "abcde" and "cdeab" should return true.

bradleyyin

func isTwinPrime (_ num: Int) -> Bool {
    guard checkPrime(num) else {
        return false
    }
    let numMinusTwo = num - 2
    let numPlusTwo = num + 2
    if checkPrime(numMinusTwo) || checkPrime(numPlusTwo) {
        return true
    } else {
        return false

bradleyyin

"Challenge 7: Condense whitespace
Difficulty: Easy

Write a function that returns a string with any consecutive spaces replaced with a single space.

Sample input and output
I've marked spaces using "[space]" below for visual purposes:

The string "a[space][space][space]b[space][space][space]c" should return "a[space]b[space]c".
The string "[space][space][space][space]a" should return "[space]a".