evgenii-malov

{-
binomial-distribution-1: https://www.hackerrank.com/challenges/binomial-distribution-1/
  Author: Evgeniy Malov <[email protected]>
  Date: Jan 4, 2025
  join me : https://www.youtube.com/@EvgeniyMalov
            https://ru.linkedin.com/in/deepwalk            
-}

import Text.Printf (printf)
-- 4 shots

evgenii-malov

{-
  random-number-generator: https://www.hackerrank.com/challenges/random-number-generator
  Author: Evgeniy Malov <[email protected]>
  Date: Jan 1, 2025
  join me : https://www.youtube.com/@EvgeniyMalov
            https://ru.linkedin.com/in/deepwalk            
-}
{-# LANGUAGE DuplicateRecordFields, FlexibleInstances, UndecidableInstances #-}

module Main where

evgenii-malov

for haskell repl:

:set prompt "\ESC[34mλ> \ESC[m"

for python repl:

sys.ps1 = '\x01\x1b[1;49;31m\x02λ>\x01\x1b[0m\x02'
sys.ps2 = '\x01\x1b[1;49;31m\x02λ>\x01\x1b[0m\x02'

evgenii-malov

fif() {
    rg  \
    --column \
    --no-heading \
    --fixed-strings \
    --ignore-case \
    --hidden \
    --follow \
    --glob '!.git/*' \
    --glob '!.vscode-server/*' \

evgenii-malov

-- video https://youtu.be/uj2N5fBZnCA
import Data.Array.MArray
import Data.Array.IO.Internals (IOArray(IOArray))
import Control.Monad.ST
import Data.Array.ST

workio = do
         a <- newArray (0,3) 'a' :: IO ( IOArray Int Char)
         writeArray a 3 'x'
         a_ <- getAssocs a

evgenii-malov

-- video https://youtu.be/RPEtIZ44RSc
import Data.Array.IArray
import Data.Char (toUpper)
-- elements that is associated with some kind of numerical index 
-- truly constant time (O(1)) access. 
-- store their data more efficiently in memory.
-- modification function must create an entirely new array (partially can be fixed with Monad context)


-- math look:

evgenii-malov

-- video https://www.youtube.com/watch?v=9JDPGvc6UmI
import Control.Monad.ST
import Data.IntMap.Strict
import Data.STRef (newSTRef, readSTRef, writeSTRef, modifySTRef)
import Control.Monad

until_ :: Monad m => m a -> m Bool -> m ()
until_ a p = do
              a
              b <- p

evgenii-malov

-- see video https://www.youtube.com/watch?v=MJscn-m4KIo&t=3943s
import Data.STRef
import Control.Monad.ST
import Data.Maybe
import Control.Monad
import Data.Either (fromRight, isLeft, fromLeft)
import Debug.Trace

data Llist s a = Llist {llen:: STRef s Int, lhead:: STRef s (Maybe (Node s a)) }

evgenii-malov

-- explain video https://youtu.be/Ln_tVErialQ
-- GHCi, version 8.8.4
{-# LANGUAGE RankNTypes    #-}
{-# LANGUAGE TypeOperators #-}
{-# OPTIONS_GHC -Wno-incomplete-patterns #-}

import PrettyT -- https://www.youtube.com/watch?v=Ud-1Z0hBlB8&t=379s
-- data Btree a = Empty | Node a (Btree a) (Btree a) deriving Show
import Data.Ord
import Data.List

evgenii-malov

-- video https://youtu.be/E8Fxtpr24Zg
-- GHCi, version 8.8.4
{-# LANGUAGE RankNTypes    #-}
{-# LANGUAGE TypeOperators #-}
{-# OPTIONS_GHC -Wno-incomplete-patterns #-}

import PrettyT -- https://www.youtube.com/watch?v=Ud-1Z0hBlB8&t=379s
-- data Btree a = Empty | Node a (Btree a) (Btree a) deriving Show
import Data.Ord
import Data.List