The two-pointer technique

One of the highest-value tricks in all of DSA: walk two indices toward each other and collapse an O(n squared) problem into a single O(n) pass. Watch it reverse an array.

18 min read

The two-pointer technique is part of DSA in Java, visualized

Chapter 1 is free - you've seen how these lessons work. Unlock the full course once and keep it for life, including every chapter still being written.

  • Read any algorithm's Big-O cost on sight, and pick the faster approach
  • Implement the core data structures in Java from scratch, not from memory
  • Recognise the pattern behind an interview problem and reach for the right tool
  • Debug your own code by watching exactly what it does, step by step

One-time payment, lifetime access. No subscription.

Back to the course overview