title: Check Whether Arithmetic Progression Can Formed Given Array
signature: function check_whether_arithmetic_progression_can_formed_given_array(arr, n)
test_code: using Printf
  
  # SOLUTION CODE
  # ============================================
  PLACEHOLDER_CODE_BODY
  
  # TESTING CODE 
  # ============================================
  function validate_solution(actual, expected)
      return actual == expected
  end
  
  function driver(arr, n, expected)
      try
  
          if validate_solution(PLACEHOLDER_FN_NAME(arr, n), expected)
              return "PASSED";
          end
          return "FAILED";
      catch exception_obj
          return string(Base.typename(typeof(exception_obj)).wrapper);
      end
  end
  
  function main()
      
      result = driver([1, 4, 16, 64], 4, false);
      @printf("TEST-0...%s\n",result);
      
      result = driver([0, 4, 8, 12], 4, true);
      @printf("TEST-1...%s\n",result);
      
      result = driver([-2, 0, 2, 4, 6], 5, true);
      @printf("TEST-2...%s\n",result);
      
      result = driver([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], 7, true);
      @printf("TEST-3...%s\n",result);
      
      result = driver([46, 56, 66, 76, 86], 5, true);
      @printf("TEST-4...%s\n",result);
      
      result = driver([46, 56, 56, 66, 76, 86], 6, false);
      @printf("TEST-5...%s\n",result);
      
      result = driver([7, 9, 11, 21, 44, 45, 61, 67, 78, 97, 98, 99], 11, false);
      @printf("TEST-6...%s\n",result);
      
      result = driver([-96, -84, -74, -70, -68, -62, -50, -50, -38, -36, -36, -36, -34, -34, -28, -28, -26, -18, -12, -4, -4, -2, -2, 6, 6, 14, 24, 34, 36, 44, 50, 54, 54, 62, 64, 66, 70, 74, 74, 78, 84, 86], 33, false);
      @printf("TEST-7...%s\n",result);
      
      result = driver([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, 1, 1, 1, 1, 1, 1, 1, 1, 1], 33, false);
      @printf("TEST-8...%s\n",result);
      
      result = driver([1, 3, 5, 11, 14, 15, 15, 17, 18, 19, 20, 20, 22, 32, 33, 35, 36, 37, 39, 44, 45, 46, 51, 54, 57, 58, 61, 61, 63, 64, 67, 69, 70, 70, 79, 82, 86, 89, 92, 93, 95, 99], 40, false);
      @printf("TEST-9...%s\n",result);
      
  end
  
  main()
source_py: def check_whether_arithmetic_progression_can_formed_given_array(arr, n):
      if (n == 1):
          return True
      arr.sort()
      d = (arr[1] - arr[0])
      for i in range(2, n):
          if ((arr[i] - arr[(i - 1)]) != d):
              return False
      return True
source_cpp: bool check_whether_arithmetic_progression_can_formed_given_array(vector<int> arr, int n) {
    if ( n == 1 ) return true;
    sort(arr.begin(), arr.end());
    int d = arr [ 1 ] - arr [ 0 ];
    for ( int i = 2;
    i < n;
    i ++ ) if ( arr [ i ] - arr [ i - 1 ] != d ) return false;
    return true;
  }