title: Maximum Sum Pairs Specific Difference
signature: maximumSumPairsSpecificDifference :: [Integer] -> Integer -> Integer -> Integer
  maximumSumPairsSpecificDifference arr n k = 
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 k expected = do
      if (validateSolution (PLACEHOLDER_FN_NAME arr n k) expected)
          then "PASSED"
      else "FAILED"
  
  main = do
      printf "TEST-0...%s\n" (driver ([48, 53, 67, 78, 78, 93, 95]) (6) (4) (156) )
  
      printf "TEST-1...%s\n" (driver ([-70, -32, -2, 18, 30, 32, 52, 70, 72, 88]) (8) (8) (62) )
  
      printf "TEST-2...%s\n" (driver ([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]) (37) (31) (10) )
  
      printf "TEST-3...%s\n" (driver ([2, 3, 5, 5, 6, 10, 12, 13, 13, 16, 23, 23, 34, 36, 39, 40, 42, 45, 45, 47, 51, 51, 52, 56, 57, 58, 60, 60, 60, 60, 61, 63, 67, 68, 71, 73, 75, 80, 80, 82, 84, 86, 86, 86, 86, 89, 90, 98, 99]) (31) (37) (1083) )
  
      printf "TEST-4...%s\n" (driver ([-84, -56, 68, 78]) (3) (3) (0) )
  
      printf "TEST-5...%s\n" (driver ([0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]) (14) (9) (5) )
  
      printf "TEST-6...%s\n" (driver ([1, 2, 3, 9, 12, 12, 16, 17, 18, 19, 20, 21, 21, 26, 29, 42, 44, 45, 48, 48, 48, 54, 54, 55, 60, 63, 63, 64, 64, 67, 67, 68, 69, 74, 78, 78, 79, 83, 95, 95, 95, 96, 97, 99]) (27) (42) (849) )
  
      printf "TEST-7...%s\n" (driver ([-92, -58, -56, -48, -42, -16, -14, 28, 40, 42, 54, 60, 64]) (9) (8) (0) )
  
      printf "TEST-8...%s\n" (driver ([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]) (21) (19) (9) )
  
      printf "TEST-9...%s\n" (driver ([25, 64, 96]) (1) (1) (0) )
  
source_py: def maximum_sum_pairs_specific_difference(arr, N, K):
      arr.sort()
      dp = ([0] * N)
      dp[0] = 0
      for i in range(1, N):
          dp[i] = dp[(i - 1)]
          if ((arr[i] - arr[(i - 1)]) < K):
              if (i >= 2):
                  dp[i] = max(dp[i], ((dp[(i - 2)] + arr[i]) + arr[(i - 1)]))
              else:
                  dp[i] = max(dp[i], (arr[i] + arr[(i - 1)]))
      return dp[(N - 1)]
source_cpp: int maximum_sum_pairs_specific_difference(vector<int> arr, int N, int K) {
    sort(arr.begin(), arr.end());
    int dp [ N ];
    dp [ 0 ] = 0;
    for ( int i = 1;
    i < N;
    i ++ ) {
      dp [ i ] = dp [ i - 1 ];
      if ( arr [ i ] - arr [ i - 1 ] < K ) {
        if ( i >= 2 ) dp [ i ] = max ( dp [ i ], dp [ i - 2 ] + arr [ i ] + arr [ i - 1 ] );
        else dp [ i ] = max ( dp [ i ], arr [ i ] + arr [ i - 1 ] );
      }
    }
    return dp [ N - 1 ];
  }