psksvp

// pairup a seq 
// [email protected]
object Pairup
{
  def main(args: Array[String]): Unit = 
  {
    println("hello")
    
    val a = List(1, 2, 3, 4, 5, 6) //even
    val b = pairup(a)

psksvp

/**
  translate from Scala by [email protected]
 http://vkostyukov.ru/posts/combinatorial-algorithms-in-scala/
 */
extension Collection
{
  func combinations(_ n: Int) -> [[Element]]
  {
    guard self.count > 0 else {return [[Element]]()}
    guard n <= self.count else {return [[Element]]()}

psksvp

//  approximate the fraction of a real
//  Created by psksvp on 22/7/20.

print(approximateFraction(0.5))
print(approximateFraction(0.5454))
print(approximateFraction(0.75))
print(approximateFraction(0.333333))
print(approximateFraction(0.888888888888))
print(approximateFraction(0.0123456789))

psksvp

I put in the make file from  https://stackoverflow.com/questions/33370175/how-do-i-completely-rename-an-xcode-project-i-e-inclusive-of-folders

It was originally written by https://stackoverflow.com/users/7641654/pietro-basso

__USE AT YOUR OWN RISK, ALWAYS BACK UP before doing this. You must read the post before using this.__

The makefile needs `ack` and `rename` which can be install with `brew install ack rename`
put this file the project directory then run `make -f renameXcode.makefile OLD_NAME="oldname" NEW_NAME="newname"`

psksvp

public extension String
{
  func intIndex(of s: String) -> Int?
  {
    if let r = self.range(of: s)
    {
      return self.distance(from: self.startIndex, to: r.lowerBound)
    }
    else
    {

psksvp

open the file */etc/default/grub* with a text editor with sudo 
change the line  

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"  

to 

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

saved, then run