title: Longest Subsequence Such That Difference Between Adjacents Is One
signature: class Solution {
  
      public int LongestSubsequenceSuchThatDifferenceBetweenAdjacentsIsOne(List<int> arr, int n) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(int actual, int expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(List<int> arr, int n, int expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                int pred_result = solution_cls.PLACEHOLDER_FN_NAME(arr, n); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  new List<int>{2, 13, 15, 17, 18, 20, 22, 24, 28, 34, 37, 43, 46, 47, 49, 51, 52, 54, 58, 64, 65, 77, 78, 79, 87, 90, 92, 93, 94, 97}, 23, 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-86, -56, 76, 86, 42, -40, 8, 34, -48, -54, -80, 6, 42, 48, 76, -26, 6}, 15, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 16, 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{5, 22, 15, 26, 29, 47, 22}, 5, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-90, -84, -76, -76, -74, -74, -66, -58, -58, -56, -56, -44, -38, -36, -34, -32, -16, -10, 2, 6, 24, 24, 24, 34, 36, 54, 60, 68, 70, 76, 88}, 17, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1}, 26, 
                  12
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{1, 3, 12, 12, 12, 12, 14, 17, 18, 19, 23, 27, 28, 30, 35, 38, 42, 44, 45, 48, 52, 59, 61, 64, 65, 69, 73, 76, 77, 82, 83, 85, 87, 99}, 23, 
                  3
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-54, -20, 24, -78, -58, 64, 34, 70, -36, -24}, 8, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{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}, 27, 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{5, 35, 75, 21, 82, 32, 28, 53, 20, 27, 42, 92, 32, 70, 81, 75, 72, 66, 97, 60, 11, 83, 14, 30, 5, 68, 17, 27, 62, 86, 26, 20, 97, 91, 44, 69}, 20, 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def longest_subsequence_such_that_difference_between_adjacents_is_one(arr, n):
      dp = [1 for i in range(n)]
      for i in range(n):
          for j in range(i):
              if ((arr[i] == (arr[j] + 1)) or (arr[i] == (arr[j] - 1))):
                  dp[i] = max(dp[i], (dp[j] + 1))
      result = 1
      for i in range(n):
          if (result < dp[i]):
              result = dp[i]
      return result
source_cpp: int longest_subsequence_such_that_difference_between_adjacents_is_one(vector<int> arr, int n) {
    int dp [ n ];
    for ( int i = 0;
    i < n;
    i ++ ) dp [ i ] = 1;
    for ( int i = 1;
    i < n;
    i ++ ) {
      for ( int j = 0;
      j < i;
      j ++ ) {
        if ( ( arr [ i ] == arr [ j ] + 1 ) || ( arr [ i ] == arr [ j ] - 1 ) ) dp [ i ] = max ( dp [ i ], dp [ j ] + 1 );
      }
    }
    int result = 1;
    for ( int i = 0;
    i < n;
    i ++ ) if ( result < dp [ i ] ) result = dp [ i ];
    return result;
  }