MichaelSelsky

import Foundation

extension Collection where Self.Iterator.Element: RandomAccessCollection {
    // PRECONDITION: `self` must be rectangular, i.e. every row has equal size.
    func transposed() -> [[Self.Iterator.Element.Iterator.Element]] {
        guard let firstRow = first else { return [] }
        return firstRow.indices.map { index in
            self.map { $0[index] }
        }
    }

MichaelSelsky

Cesarian Cypher

Encoding/Decoding a string using a cypher with an arbitray offset

Process

• Generate an encoding dictionary that maps an original value to a new value based on an offset
• Use enc_dict to write an encoded string
• Generate a decoding dict that maps an encoded value back to the original based on the negative offset
• Reverse the encoding

Ensures understanding of

MichaelSelsky

import random

# Most of this code is more advanced than what I'd expect from the students. Lots of list comprehension that can be replaced with loops

def removePunctuation(s):
    '''
    Remove all the punctuation and replace with spaces.
    '''
    return ''.join(ch if ch not in string.punctuation else ' ' for ch in s)

MichaelSelsky

### Keybase proof

I hereby claim:

  * I am michaelselsky on github.
  * I am michaelselsky (https://keybase.io/michaelselsky) on keybase.
  * I have a public key whose fingerprint is AAF3 A478 926A 06B2 9B18  343F CA4D 4AF6 9BC6 7870

To claim this, I am signing this object:

MichaelSelsky

let giga = 1000000000
let mega = 1000000
let kilo = 1000

let fileSize = 20*giga
let serverUploadSpeed = 20*mega
let clientDownloadSpeed = 2*mega

func serverTime(numberOfClients: Int, uploadSpeedOfClients: Int) -> Int {
    let serverToUploadNFiles = numberOfClients * fileSize / serverUploadSpeed