Two Pointers — Algorithm Visualizer

Step 1:Find two numbers that sum to 14 in a sorted array. Left starts at index 0, right at the end.

Two Pointers

Intermediate
Time Complexity
O(n²)O(n log n)O(n)O(log n)O(1)n →
O(n)

Two Pointers is a technique where two indices move through a data structure (usually an array) to solve problems efficiently.

Common patterns:

  • Left & Right: start from both ends, move inward
  • Slow & Fast: both start from beginning at different speeds

Time Complexity: O(n) — each pointer moves at most n times

Space Complexity: O(1) — only two variables

Classic problems:

  • Two Sum (sorted array)
  • Container with most water
  • Remove duplicates in-place
  • Palindrome checking
  • Linked list cycle detection (slow/fast)

Related algorithms

Frequently asked questions

What is Two Pointers?
Two Pointers is a technique where two indices move through a data structure (usually an array) to solve problems efficiently.
What is the complexity of Two Pointers?
Time (average): O(n) · Space: O(1)
Who is this Two Pointers visualizer for?
The Two Pointers visualization targets intermediate-level learners in the Concepts category. Useful for students, interview prep, and hands-on review.
What algorithms are related to Two Pointers?
In the same category (Concepts) you can explore: Big O Notation, Recursion, Sliding Window. Each has an interactive visualization.