title: Longest Subsequence Such That Difference Between Adjacents Is One
signature: pub fn longest_subsequence_such_that_difference_between_adjacents_is_one(arr: Vec<i32>, n: i32) -> i32 {
test_code: use std::collections::HashMap;
  use std::collections::HashSet;
  use std::cmp::*;
  use std::collections::*;
  use std::fmt::*; 
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  pub fn validate_solution(actual: i32, expected: i32)->bool{
  return actual==expected
  }
  pub fn driver(arr: Vec<i32>, n: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(arr, n), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        Vec::from([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
      ));
      
      println!("TEST-1...{}", driver(
        Vec::from([-86, -56, 76, 86, 42, -40, 8, 34, -48, -54, -80, 6, 42, 48, 76, -26, 6]), 15, 
        1
      ));
      
      println!("TEST-2...{}", driver(
        Vec::from([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
      ));
      
      println!("TEST-3...{}", driver(
        Vec::from([5, 22, 15, 26, 29, 47, 22]), 5, 
        1
      ));
      
      println!("TEST-4...{}", driver(
        Vec::from([-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
      ));
      
      println!("TEST-5...{}", driver(
        Vec::from([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
      ));
      
      println!("TEST-6...{}", driver(
        Vec::from([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
      ));
      
      println!("TEST-7...{}", driver(
        Vec::from([-54, -20, 24, -78, -58, 64, 34, 70, -36, -24]), 8, 
        1
      ));
      
      println!("TEST-8...{}", driver(
        Vec::from([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
      ));
      
      println!("TEST-9...{}", driver(
        Vec::from([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
      ));
      
  }
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;
  }