From a20d6323d8ec4341e6fcd1d03ee9573287195eb9 Mon Sep 17 00:00:00 2001
From: Neil Smith <NeilNjae@users.noreply.github.com>
Date: Thu, 23 Nov 2023 15:46:54 +0000
Subject: [PATCH] Done several tasks

---
 app/cses1622.hs              |   22 +
 app/cses1623.hs              |   18 +
 app/cses1624.hs              |   38 ++
 app/cses1755.hs              |   26 +
 app/cses2165.hs              |   17 +
 app/cses2205.hs              |   20 +
 app/cses2431.hs              |   52 ++
 cses-programming-tasks.cabal |   30 +
 data/cses1623.txt            |    2 +
 data/cses1624.txt            |    8 +
 data/cses2431.txt            |    4 +
 data/cses2431a.txt           | 1001 ++++++++++++++++++++++++++++++++++
 12 files changed, 1238 insertions(+)
 create mode 100644 app/cses1622.hs
 create mode 100644 app/cses1623.hs
 create mode 100644 app/cses1624.hs
 create mode 100644 app/cses1755.hs
 create mode 100644 app/cses2165.hs
 create mode 100644 app/cses2205.hs
 create mode 100644 app/cses2431.hs
 create mode 100644 data/cses1623.txt
 create mode 100644 data/cses1624.txt
 create mode 100644 data/cses2431.txt
 create mode 100644 data/cses2431a.txt

diff --git a/app/cses1622.hs b/app/cses1622.hs
new file mode 100644
index 0000000..8925b05
--- /dev/null
+++ b/app/cses1622.hs
@@ -0,0 +1,22 @@
+import Data.List (sort, inits, tails, nub)
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  let base = sort line1
+  let perms = permutations base
+  print $ length perms
+  putStrLn $ unlines perms
+
+permutations :: String -> [String]
+
+permutations [] = []
+permutations (x:[]) = [[x]]
+permutations xs = concatMap (\(y, ys) -> map (y:) (permutations ys)) (selects xs)
+
+selects :: String -> [(Char, String)]
+selects [] = []
+selects xs = nub [(head t, h ++ (tail t))
+                 | (h, t) <- zip (inits xs) (tails xs)
+                 , not (null t)]
+
diff --git a/app/cses1623.hs b/app/cses1623.hs
new file mode 100644
index 0000000..7121018
--- /dev/null
+++ b/app/cses1623.hs
@@ -0,0 +1,18 @@
+import Data.List (sort)
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  line2 <- getLine
+  let nums = reverse $ sort $ map read $ words line2 :: [Int]
+  print $ solve nums
+
+
+solve (x:xs) = minimum diffs
+  where s = x + sum xs
+        ys = powerSet xs
+        diffs = [abs (s - 2 * (sum y)) | y <- ys]
+
+powerSet :: [a] -> [[a]]
+powerSet [] = [[]]
+powerSet (x:xs) = powerSet xs ++ map (x:) (powerSet xs)
diff --git a/app/cses1624.hs b/app/cses1624.hs
new file mode 100644
index 0000000..d984ffe
--- /dev/null
+++ b/app/cses1624.hs
@@ -0,0 +1,38 @@
+import Data.List
+import qualified Data.Set as S
+import Control.Monad
+
+data Queen = Queen Int Int -- row, column
+  deriving (Show, Eq, Ord)
+
+main :: IO ()
+main = do
+  text <- getContents
+  let grid = mkGrid text
+  -- print grid
+  let solutions = solve grid
+  print $ length solutions
+
+solve :: S.Set Queen -> [S.Set Queen]
+solve forbiddens =
+  do cols <- permutations [0..7]
+     let queens = S.fromList [uncurry Queen p | p <- zip [0..7] cols]
+     guard $ S.null $ S.intersection queens forbiddens
+     let posDiagonals = S.map posDiagonalOf queens
+     let negDiagonals = S.map negDiagonalOf queens
+     guard $ S.size posDiagonals == 8
+     guard $ S.size negDiagonals == 8
+     return queens
+
+posDiagonalOf, negDiagonalOf :: Queen -> Int
+posDiagonalOf (Queen r c) = c - r
+negDiagonalOf (Queen r c) = c + r
+
+mkGrid :: String -> S.Set Queen
+mkGrid text = S.fromList forbiddens
+  where rows = lines text
+        r = length rows - 1
+        c = (length $ head rows) - 1
+        forbiddens = [Queen i j | i <- [0..r], j <- [0..c], rows !! i !! j == '*' ]
+
+
diff --git a/app/cses1755.hs b/app/cses1755.hs
new file mode 100644
index 0000000..ff5d217
--- /dev/null
+++ b/app/cses1755.hs
@@ -0,0 +1,26 @@
+import qualified Data.Map.Strict as M
+import Data.Map.Strict ((!))
+
+type LetterCount = M.Map Char Int
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  let counts = countLetters line1
+  if palindromable counts
+    then putStrLn $ showPalindrome counts
+    else putStrLn "NO SOLUTION"
+
+countLetters :: String -> LetterCount
+countLetters = foldr (\c m -> M.insertWith (+) c 1 m) M.empty  
+
+palindromable :: LetterCount -> Bool
+palindromable = (<= 1) . M.size . M.filter odd
+
+showPalindrome :: LetterCount -> String
+showPalindrome counts = showStart ++ showMid ++ showEnd
+  where 
+    (odds, evens) = M.partition odd counts
+    showStart = mconcat [replicate (n `div` 2) l | (l, n) <- M.toAscList evens]
+    showMid = mconcat [replicate n l | (l, n) <- M.toAscList odds]
+    showEnd = mconcat [replicate (n `div` 2) l | (l, n) <- M.toDescList evens]
diff --git a/app/cses2165.hs b/app/cses2165.hs
new file mode 100644
index 0000000..1b6c71b
--- /dev/null
+++ b/app/cses2165.hs
@@ -0,0 +1,17 @@
+data Move = Move Int Int
+  -- deriving (Show)
+
+instance Show Move where
+  show (Move a b) = show a ++ " " ++ show b
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  let nDisks = read line1 :: Int
+  let moves = solve nDisks 1 2 3
+  print $ length moves
+  putStrLn $ unlines $ map show moves
+
+solve :: Int -> Int -> Int -> Int -> [Move]
+solve 0 _ _ _ = []
+solve n a b c = solve (n-1) a c b ++ [Move a c] ++ solve (n-1) b a c
diff --git a/app/cses2205.hs b/app/cses2205.hs
new file mode 100644
index 0000000..e9fa3d5
--- /dev/null
+++ b/app/cses2205.hs
@@ -0,0 +1,20 @@
+import Data.Word
+import Data.Bits
+import Numeric (showIntAtBase)
+import Data.Char (intToDigit)
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  let nBits = read line1 :: Int
+  let n = fromIntegral $ 2 ^ nBits
+  let codes = [toGray x | x <- [0..(n - 1)]]
+  putStrLn $ unlines $ map (showBits nBits) codes
+  
+toGray :: Word16 -> Word16
+toGray n = n `xor` (n `shiftR` 1)
+
+showBits :: Int -> Word16 -> String
+showBits k n = prefix ++ suffix
+  where suffix = showIntAtBase 2 intToDigit n ""
+        prefix = replicate (k - length suffix) '0'
\ No newline at end of file
diff --git a/app/cses2431.hs b/app/cses2431.hs
new file mode 100644
index 0000000..bebaf9d
--- /dev/null
+++ b/app/cses2431.hs
@@ -0,0 +1,52 @@
+import Data.List
+import Control.Monad
+
+main :: IO ()
+main = do
+  line1 <- getLine
+  let numQuestions = read line1 :: Int
+  answers <- forM [1..numQuestions] $ \_ -> do
+    line <- getLine
+    -- print (">> " ++ line)
+    let question = read line
+    -- print $ ("<> " ++ (show $ skipPlaces question))
+    return $ skipPlaces question
+  putStrLn $ unlines $ map show answers
+
+
+-- lenUpTo, startOf, calcStartOfPiece, calcStartOf :: Integer -> Integer
+-- lenUpTo n = fromIntegral $ length $ mconcat $ map show $ takeWhile (< n) [1..]
+
+-- startOf n = (lenUpTo n) + 1
+
+-- calcStartOfPiece n 
+--   | n < 10 = n
+--   | n < 100 = 2 * (n - 10) + 9 + 1
+--   | n < 1000 = 3 * (n - 100) + (90 * 2) + 9 + 1
+--   | n < 10000 = 4 * (n - 1000) + (900 * 3) + (90 * 2) + 9 + 1
+
+-- calcStartOf n = (k + 1) * (n - 10 ^ k) + smaller
+--   where k = discreteLog n
+--         smaller = 1 + sum [9 * 10 ^ (i - 1) * i | i <- [1..k]]
+
+-- discreteLog :: Integer -> Integer
+-- discreteLog n = go n 0
+--   where go k p
+--           | k < 10 = p
+--           | otherwise = go (k `div` 10) (p + 1)
+
+
+-- cbStart n = (startOf n, calcStartOf n, calcStartOfPiece n)
+
+prefixLengths :: [Integer]
+prefixLengths = scanl' f 0 [1..]
+  where f acc i = acc + 9 * 10 ^ (i - 1) * i
+
+skipPlaces :: Integer -> Integer
+skipPlaces n = read [(show thisNum) !! (fromIntegral(n - (prevNumsLen + lowerOrders + 1)))]
+  where -- k = discreteLog n
+        k = fromIntegral $ (length $ takeWhile (< n) prefixLengths) - 1
+        lowerOrders = prefixLengths !! (fromIntegral k)
+        prevNums = ((n - (lowerOrders + 1)) `div` (k + 1))
+        prevNumsLen = prevNums * (k + 1)
+        thisNum = prevNums + (10 ^ k)
diff --git a/cses-programming-tasks.cabal b/cses-programming-tasks.cabal
index 62ea302..a1cde74 100644
--- a/cses-programming-tasks.cabal
+++ b/cses-programming-tasks.cabal
@@ -133,4 +133,34 @@ executable cses1618
 executable cses1754
   import: build-directives
   main-is: cses1754.hs
+
+executable cses1755
+  import: build-directives
+  main-is: cses1755.hs
+  build-depends: containers
+  
+executable cses2205
+  import: build-directives
+  main-is: cses2205.hs
+  
+executable cses2165
+  import: build-directives
+  main-is: cses2165.hs
+
+executable cses1622
+  import: build-directives
+  main-is: cses1622.hs
+
+executable cses1623
+  import: build-directives
+  main-is: cses1623.hs
+
+executable cses1624
+  import: build-directives
+  main-is: cses1624.hs
+  build-depends: containers
+
+executable cses2431
+  import: build-directives
+  main-is: cses2431.hs
   
\ No newline at end of file
diff --git a/data/cses1623.txt b/data/cses1623.txt
new file mode 100644
index 0000000..b9679f8
--- /dev/null
+++ b/data/cses1623.txt
@@ -0,0 +1,2 @@
+5
+3 2 7 4 1
diff --git a/data/cses1624.txt b/data/cses1624.txt
new file mode 100644
index 0000000..994f68d
--- /dev/null
+++ b/data/cses1624.txt
@@ -0,0 +1,8 @@
+........
+........
+..*.....
+........
+........
+.....**.
+...*....
+........
diff --git a/data/cses2431.txt b/data/cses2431.txt
new file mode 100644
index 0000000..3737d84
--- /dev/null
+++ b/data/cses2431.txt
@@ -0,0 +1,4 @@
+3
+7
+19
+12
diff --git a/data/cses2431a.txt b/data/cses2431a.txt
new file mode 100644
index 0000000..32415cd
--- /dev/null
+++ b/data/cses2431a.txt
@@ -0,0 +1,1001 @@
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+23
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+403
-- 
2.34.1