title: Chocolate Distribution Problem
signature: chocolateDistributionProblem :: [Integer] -> Integer -> Integer -> Integer
  chocolateDistributionProblem arr n m = 
test_code: import Text.Printf
  import Control.Exception (catch, SomeException)
  import Data.Typeable
  import qualified Data.List as List
  import qualified Data.Map as Map
  import qualified Data.Set as Set
  
  -- SOLUTION CODE
  -- ============================================
  
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  validateSolution :: Integer -> Integer -> Bool
  validateSolution actual expected = do
      actual == expected
  
  
  driver :: [Integer] -> Integer -> Integer -> Integer -> String
  driver arr n m expected = do
      if (validateSolution (PLACEHOLDER_FN_NAME arr n m) expected)
          then "PASSED"
      else "FAILED"
  
  main = do
      printf "TEST-0...%s\n" (driver ([2, 5, 11, 23, 33, 35, 39, 51, 52, 56, 74, 76, 76, 79, 85, 88, 93, 98]) (16) (13) (65) )
  
      printf "TEST-1...%s\n" (driver ([-94, -94, -88, -84, -74, -70, -56, -50, -48, -42, -34, -24, -18, -14, 0, 4, 4, 16, 16, 30, 36, 42, 52, 56, 72, 74, 76, 84, 88]) (15) (28) (-1) )
  
      printf "TEST-2...%s\n" (driver ([0, 0, 1, 1, 1, 1]) (5) (5) (1) )
  
      printf "TEST-3...%s\n" (driver ([3, 4, 5, 5, 12, 16, 16, 16, 18, 29, 37, 38, 40, 43, 44, 49, 57, 60, 62, 63, 67, 69, 73, 74, 75, 76, 78, 84, 85, 86, 88, 89, 92]) (25) (18) (57) )
  
      printf "TEST-4...%s\n" (driver ([-98, -80, -50, -44, -42, -36, -36, -28, -10, -8, -4, -2, 2, 10, 18, 18, 26, 32, 36, 56, 80, 86, 88, 90]) (16) (12) (60) )
  
      printf "TEST-5...%s\n" (driver ([0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]) (13) (14) (-1) )
  
      printf "TEST-6...%s\n" (driver ([13, 15, 62, 65, 87]) (3) (4) (-1) )
  
      printf "TEST-7...%s\n" (driver ([-92, -88, -88, -80, -76, -62, -60, -60, -50, -48, -36, -36, -32, -26, -14, -8, 4, 18, 18, 22, 28, 30, 30, 32, 48, 48, 58, 60, 64, 72, 78, 82, 94]) (31) (17) (90) )
  
      printf "TEST-8...%s\n" (driver ([0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1]) (9) (6) (1) )
  
      printf "TEST-9...%s\n" (driver ([17, 23, 25, 38, 40, 53, 58, 73, 77]) (8) (6) (35) )
  
source_py: def chocolate_distribution_problem(arr, n, m):
      if ((m == 0) or (n == 0)):
          return 0
      arr.sort()
      if (n < m):
          return (- 1)
      min_diff = sys.maxsize
      first = 0
      last = 0
      i = 0
      while (((i + m) - 1) < n):
          diff = (arr[((i + m) - 1)] - arr[i])
          if (diff < min_diff):
              min_diff = diff
              first = i
              last = ((i + m) - 1)
          i += 1
      return (arr[last] - arr[first])
source_cpp: int chocolate_distribution_problem(vector<int> arr, int n, int m) {
    if ( m == 0 || n == 0 ) return 0;
    sort(arr.begin(), arr.end());
    if ( n < m ) return - 1;
    int min_diff = INT_MAX;
    int first = 0, last = 0;
    for ( int i = 0;
    i + m - 1 < n;
    i ++ ) {
      int diff = arr [ i + m - 1 ] - arr [ i ];
      if ( diff < min_diff ) {
        min_diff = diff;
        first = i;
        last = i + m - 1;
      }
    }
    return ( arr [ last ] - arr [ first ] );
  }