class Solution:
  def findLASLength(self, nums):
    
    # DP array that stores LAS and index i and relation < or > between consecutive numbers 
    longest_alt = [(1, '.')] * len(nums) # . is an initial value 
    
    for i in range(1, len(nums)):
      if nums[i] < nums[i - 1]: # search for the > and take the LAS + 1
        for j in range(i - 1, - 1,  - 1):
          if longest_alt[j][1] == '>' or longest_alt[j][1] == '.':
            longest_alt[i] = (longest_alt[j][0] + 1, '<')
            break
      elif nums[i] > nums[i - 1]: # search for the < and take the LAS + 1
        for j in range(i - 1, - 1,  - 1):
          if longest_alt[j][1] == '<' or longest_alt[j][1] == '.':
            longest_alt[i] = (longest_alt[j][0] + 1, '>')
            break
      else: # clone the previous result
        longest_alt[i] = longest_alt[i - 1]

    return longest_alt[-1][0]