Two pointers: turning O(n²) scans into one pass
Two indexes moving with a purpose can replace nested loops. The trick is knowing which pointer to move and why it is safe to skip what you skip.
WRITING / NOTES FROM THE FORGE
Algorithms
4 articles tagged Algorithms.
Binary search is a decision rule, not a trick
Once you see binary search as "find the first place a condition becomes true", a whole family of interview problems collapses into one template.
Graph Algorithms Every Developer Should Know: BFS, DFS, and Dijkstra
Graph algorithms every developer should know: when to use BFS, DFS, or Dijkstra, how each works, and correct Python code for routing and dependency problems.
Big O Notation Explained With Practical Examples
Big O notation explained with real code: how to read O(1), O(log n), O(n log n) and O(n²), drop constants correctly, and reason about space as well as time.