amacgillivray

Solving Perfect Numbers Quickly with Haskell

Walking through the stages of optimizing a perfect-number algorithm; starting with a naive approach, rewriting to use the Euclid-Euler theorem, and then leveraging the Miller-Rabin primality test.

A Frustratingly Naive Solution

On a dark and stormy night in Kansas, many years ago, I sat in front of my laptop - face lit only by the screen.

A homework assignment had tasked us with writing a basic haskell function to find every perfect number between 1 and 9000. We weren't studying numbers, nor did we discuss perfect numbers in class. The number "9000" was chosen as the upper limit due to the complexity associated with finding perfects using typical methods.

storopoli

quitOnTopLevelReturn: true
os:
  edit: "zed {{filename}}"
  editAtLine: "zed {{filename}}:{{line}}"
git:
  autoFetch: false
  paging:
    colorArg: always
    #pager: delta --dark --paging=never
    pager: delta --dark --paging=never --line-numbers --hyperlinks --hyperlinks-file-link-format="lazygit-edit://{path}:{line}"

ziqiq

Installation for End User

1. Install flatpak builder

flatpak install --user org.flatpak.Builder

2. Build and install the Sparrow manifest

storopoli

// In general there are two properties for traits to satisfy 
// in order them to be object-safe:
//
//    1. The return type isn’t Self.
//    2. There are no generic type parameters.


// Here's an example of a non-object-safe Trait
trait MyTrait {
    fn f(&self) -> Self;

HyperCrowd

Crippling Facebook

Facebook works with advertisers to target you. These instructions are one of the many ways to begin crippling that relationship. When AI targeting is crippled, your psychosecurity improves :)

1. On your desktop machine, goto https://accountscenter.facebook.com/ads/audience_based_advertising
2. Maximize the browser window
3. Press F12 and click on the Console tab
4. Select the code below, copy it, paste it upon the Console line (The area next to the > character in the Console window), and press enter:

nikolovlazar

[
  // Navigation
  {
    "key": "ctrl-h",
    "command": "workbench.action.navigateLeft"
  },
  {
    "key": "ctrl-l",
    "command": "workbench.action.navigateRight"
  },

lavafroth

[keys.normal]
C-g = [":new", ":insert-output lazygit", ":buffer-close!", ":redraw"]

storopoli

-------------------------------------------------------------------------------
-- DEPENDENCIES
-- neovim >=0.12 ripgrep fd fzf
-------------------------------------------------------------------------------

-- Options
-- Set highlight on search
vim.o.hlsearch = false
vim.o.incsearch = true
vim.o.nu = true

storopoli

{
  "name": "Alpine",
  "image": "mcr.microsoft.com/devcontainers/base:alpine",
  
  "postCreateCommand": "sudo apk update && sudo apk add <PKGS>"
}

RobinLinus

Covenants with CAT and ECDSA

In his article, CAT and Schnorr Tricks I, Andrew Poelstra showed how to emulate OP_CHECKSIGFROMSTACK-like covenants using only OP_CATand Schnorr signatures.

Here, we show that a similar trick is possible to emulate covenants using only OP_CAT and ECDSA signatures.

The High-Level Idea

Recall the ECDSA Signature Equation