Arrays

The foundation of 90% of coding interviews

3 posts

Next Permutation: Visualizing the Lexicographical Step

See why Next Permutation is about finding the rightmost ascent. Interactive visualizer shows how one scan from the right transforms O(n!) brute force into O(n).

9 min read

LeetcodeArrays

Two Sum: The Hash Map Trick That Drops O(n²) to O(n)

See why Two Sum is just an existence check. Interactive visualizer shows how one equation turns O(n²) brute force into O(n) with hash maps.

8 min read

LeetcodeArrays

Sliding Window Algorithm: Why O(n²) is Just Bad Memory

Visualize why O(n²) is inefficient through a heat map simulator. Watch brute force burn CPU cycles while sliding window glides smoothly.

15 min read