Solve a non-standard variant of LIS

Problem

A non-standard variant of Longest Increasing Subsequence (LIS).

Approach

• Start from the classic O(n log n) patience-sorting / binary-search LIS
• Adapt the DP recurrence to the variant's twist (e.g., constraints on adjacency, differences, or grouping)
• Discuss the DP state and how the variation changes the transitions

Note

The exact twist is non-standard — clarify the variant's rules with the interviewer before coding.