Using Python3,not very good on the memory management [Critiques Open]
IntuitionThe problem requires finding the longest subsequence where the absolute differences between consecutive elements are non-increasing. This means each su
# Intuition
The problem requires finding the longest subsequence where the absolute differences between consecutive elements are non-increasing. This means each subsequent difference must be less than or equal to the previous one. To tackle this efficiently, dynamic programming (DP) is used to track valid subsequences while leveraging the constraints on input values (1 to 300).

# Approach
1.max_for_x: A 2D array where max_for_x[x][d] stores the maximum length of subsequences ending with value x and a last difference of d.

2.suffix_max_for_x: A 2D array where suffix_max_for_x[x][d] tracks the maximum subsequence length for value x with differences ≥ d. This optimizes lookups for valid transitions.

3.For each element y in the array, iterate over all possible previous values x (1 to 300).

4.Compute the new difference d_new = |y - x|.

5.Use suffix_max_for_x to find the longest valid subsequence ending at x with a difference ≥ d_new, ensuring the non-increasing property.
# Complexity
- Time complexity:
 O(n × 300)

        For each of the n elements, we process up to 300 possible previous values and differences.
- Space complexity:
O(300 × 300)

        Fixed space for the DP arrays due to the constraints on input values.
# Code
```python3 []

class Solution:
    def longestSubsequence(self, nums: List[int]) -> int:
        MAX_VAL = 300
        max_for_x = [[0] * 300 for _ in range(MAX_VAL + 1)]
        suffix_max_for_x = [[0] * 300 for _ in range(MAX_VAL + 1)]
        seen = [False] * (MAX_VAL + 1)
        result = 1  # Minimum possible subsequence length is 1
        
        for y in nums:
            current_max = [0] * 300
            current_single = 1  # Subsequence consisting of y alone
            
            # Iterate over all possible previous values x (1 to 300)
            for x in range(1, MAX_VAL + 1):
                if not seen[x]:
                    continue  # Skip if x hasn't been encountered before
                d_new = abs(y - x)
                if d_new >= 300:
                    continue
                # Get the maximum length from x's suffix_max where difference >= d_new
                prev_max = suffix_max_for_x[x][d_new]
                if prev_max == 0:
                    candidate_length = 2  # x followed by y forms a new subsequence
                else:
                    candidate_length = prev_max + 1
                if candidate_length > current_max[d_new]:
                    current_max[d_new] = candidate_length
            
            # Compute the suffix_max for the current y's current_max
            suffix_max_y = [0] * 300
            current_max_suffix = current_single  # At least 1 for subsequence [y]
            for d in reversed(range(300)):
                current_max_suffix = max(current_max_suffix, current_max[d])
                suffix_max_y[d] = current_max_suffix
            
            # Update the max and suffix_max for y
            max_for_x[y] = current_max.copy()
            suffix_max_for_x[y] = suffix_max_y
            # Update the result with the maximum length found for y
            result = max(result, current_max_suffix)
            
            # Mark y as seen
            seen[y] = True
        
        return result
```
['Array', 'Dynamic Programming', 'Python3']