title: Longest Subsequence Such That Difference Between Adjacents Is One
signature: func longestSubsequenceSuchThatDifferenceBetweenAdjacentsIsOne(arr []int, n int) int {
test_code: package main
  
  import (
      "fmt"
      "reflect"
      "math"
      "sort"
  )
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  func validateSolution(actual int, expected int) bool {
      return reflect.DeepEqual(actual,expected)
  }
  
  func driver(arr []int, n int, expected int) string {
      if validateSolution(PLACEHOLDER_FN_NAME(arr, n),expected) {
              return "PASSED"
      }
      return "FAILED"
  
  }
  
  func main() {
  
      // Use imports to avoid undefined errors
      var _ = reflect.DeepEqual
      _ = math.Abs
      _ = sort.Sort
      result := ""
      result = driver([]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)
      fmt.Printf("TEST-0...%s\n", result)
      
      result = driver([]int{-86, -56, 76, 86, 42, -40, 8, 34, -48, -54, -80, 6, 42, 48, 76, -26, 6}, 
  	15, 1)
      fmt.Printf("TEST-1...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-2...%s\n", result)
      
      result = driver([]int{5, 22, 15, 26, 29, 47, 22}, 
  	5, 1)
      fmt.Printf("TEST-3...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-4...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-5...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-6...%s\n", result)
      
      result = driver([]int{-54, -20, 24, -78, -58, 64, 34, 70, -36, -24}, 
  	8, 1)
      fmt.Printf("TEST-7...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-8...%s\n", result)
      
      result = driver([]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)
      fmt.Printf("TEST-9...%s\n", 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;
  }