Problem:
Score : 100 points

Problem Statement

There are three houses on a number line: House 1, 2 and 3, with coordinates A, B and C, respectively.
Print Yes if we pass the coordinate of House 3 on the straight way from House 1 to House 2 without making a detour, and print No otherwise.

Constraints

0\leq A,B,C\leq 100

A, B and C are distinct integers.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print Yes if we pass the coordinate of House 3 on the straight way from House 1 to House 2 without making a detour, and print No otherwise.

Sample Input 1

3 8 5

Sample Output 1

Yes

We pass the coordinate 5 on the straight way from the house at coordinate 3 to the house at coordinate 8.

Sample Input 2

7 3 1

Sample Output 2

No

Sample Input 3

10 2 4

Sample Output 3

Yes

Sample Input 4

31 41 59

Sample Output 4

No

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)


import qualified Data.Vector.Unboxed as V
import Data.Array.IArray (listArray, accumArray, (!))
import Data.Array.MArray
import Data.Array.ST (STUArray, runSTUArray)
import Data.Array.Unboxed (UArray)
import Data.List (sortOn, sortBy, unfoldr, partition)
import Data.Char (isSpace)
import Control.Monad.ST (ST)
import Control.Monad.Trans.State (StateT(..))
import qualified Data.ByteString.Char8 as B

-- utility functions

--   Input functions
readInt = B.readInt . B.dropWhile isSpace

readInts :: Int -> B.ByteString -> [Int]
readInts n = take n . unfoldr readInt

readIntsV :: Int -> B.ByteString -> V.Vector Int
readIntsV n = V.unfoldrN n readInt

readIntsA :: Int -> B.ByteString -> UArray Int Int
readIntsA n bs = runSTUArray $ do
  arr <- newArray_ (0,n-1)
  go arr 0 bs
  return arr
  where
    go :: STUArray s Int Int -> Int -> B.ByteString -> ST s ()
    go arr i bs
      | i==n = return ()
      | otherwise = do
        let Just (x,bs') = readInt bs
        writeArray arr i x
        go arr (i+1) bs'

readTsV :: Int -> B.ByteString -> V.Vector (Int,Int)
readTsV n = V.unfoldrN n $ runStateT ((,) <$> StateT readInt <*> StateT readInt)

readTs :: Int -> B.ByteString -> [(Int,Int)]
readTs n = take n . unfoldr readT where
  readT = runStateT ((,) <$> StateT readInt <*> StateT readInt)

-- main

yesno True = putStrLn "Yes"
yesno False = putStrLn "No"

main = do
  [a,b,c] <- map read . words <$> getLine :: IO [Int]
  if a<b then
    yesno $ a<=c && c<=b
  else
    yesno $ b<=c && c<=a