Connected Components

Subtitle / Summary Do not start this problem by memorizing a Union-Find template. Start from the pressure: each land cell looks like one island at first, but adjacent land cells must collapse into one connected component. Reading time: 10-12 min Tags: Hot100, Union-Find, DSU, matrix, connected components SEO keywords: LeetCode 200, Number of Islands, Union-Find, DSU, connected components Meta description: A pressure-first Python guide to LeetCode 200 that derives land-only count, 2D-to-1D ids, Union-Find merges, and the final runnable solution. Problem Requirement You are given an m x n 2D character grid: ...

A systematic walkthrough of Pregel (BSP) and GAS (Gather-Apply-Scatter), focused on execution paths, convergence strategies, and engineering trade-offs for PageRank, Connected Components, and parallel BFS.

Subtitle / Abstract Components are foundational for graph algorithms: undirected graphs ask “are nodes connected,” while directed graphs ask “are nodes mutually reachable.” Following the ACERS template, this article moves from naive methods to Tarjan / Kosaraju, then shows production graph-database use cases with runnable multi-language code. Estimated reading time: 14-18 minutes Tags: Graph Theory, Connected Components, SCC, Tarjan SEO keywords: Connected Components, SCC, Tarjan, Kosaraju, graph database Meta description: From undirected connected components to directed SCCs, with clear Tarjan/Kosaraju mechanics, complexity, and production rollout guidance. Target Audience Learners who need BFS/DFS to become second nature Engineers doing subgraph analysis and partition planning in graph-database systems Intermediate developers who want one unified framework for “undirected CC + directed SCC” Background / Motivation In production, you quickly hit three types of questions: ...