Alien Dictionary: Topological Sort from Word Ordering
Derive character ordering from sorted alien words using topological sort, with course schedule variants and prerequisite chain problems.
·10 min read · #dsa#graphs#advanced
#graphs
35 posts · page 1 of 1
Bipartite Graph Check: BFS 2-Coloring and DFS Approaches
Learn how to check if a graph is bipartite using BFS 2-coloring and DFS, with applications in matching, scheduling, and conflict detection.
·10 min read · #dsa#graphs#intermediate
Clone Graph, Valid Tree, and Graph Transformations
Learn to clone graphs with BFS and DFS, validate graph trees, find minimum height trees via centroid decomposition, and reconstruct itineraries with Hierholzer's algorithm.
·12 min read · #dsa#graphs#intermediate
Connected Components: DFS, BFS, and Union-Find Approaches
Master finding connected components using DFS, BFS, and Union-Find with applications to counting islands and grid connectivity problems.
·11 min read · #dsa#graphs#intermediate
Detecting Negative Cycles in Graphs
Learn how to detect negative cycles using Bellman-Ford's nth relaxation, SPFA algorithm, and apply it to arbitrage detection in currency exchange graphs.
·14 min read · #dsa#graphs#advanced
Flood Fill, Surrounded Regions, and Enclaves
Master flood fill, surrounded regions, number of enclaves, and Pacific Atlantic water flow using DFS and BFS grid traversal techniques in Python.
·12 min read · #dsa#graphs#intermediate
Graph Interview Patterns: Complete Guide
Master the top 20 graph interview patterns with a BFS vs DFS decision flowchart, Union-Find strategies, grid vs adjacency list trade-offs, and template code.
·14 min read · #dsa#graphs#interviews
Minimum Spanning Tree: Applications and Variants
Explore MST applications in network design, clustering, and competitive programming with second-best MST, critical edges, and minimum cost to connect points.
·11 min read · #dsa#graphs#intermediate
Shortest Path in Grid: BFS, 0-1 BFS, and Dijkstra on Grids
Master shortest path algorithms on grids including BFS for unweighted grids, 0-1 BFS with deque, and Dijkstra for weighted terrain with obstacles and portals.
·12 min read · #dsa#graphs#intermediate
Word Search, Boggle Solver, and Word Ladder: Grid + String Graph Problems
Solve word search with DFS backtracking, Boggle with Trie pruning, and word ladder with BFS for efficient string transformation problems.
·11 min read · #dsa#graphs#advanced
A* Search Algorithm: Heuristic Pathfinding Explained
Learn the A* search algorithm with f=g+h, admissible heuristics, grid pathfinding, and Python implementation compared to Dijkstra and BFS.
·12 min read · #dsa#graphs#advanced
Articulation Points and Bridges in Graphs
Find critical nodes and edges in graphs using Tarjan's algorithm with discovery and low-link arrays, with Python code and network applications.
·10 min read · #dsa#graphs#advanced
Euler Path and Circuit: Hierholzer's Algorithm
Understand Euler paths, circuits, and Hamiltonian differences with Hierholzer's algorithm, degree conditions, and Python implementations.
·12 min read · #dsa#graphs#advanced
Graph Coloring: Algorithms and Real-World Applications
Learn graph coloring with greedy coloring, bipartite check via 2-coloring, m-coloring with backtracking, and applications in scheduling.
·12 min read · #dsa#graphs#advanced
Graph Problems on Matrices: Grids as Implicit Graphs
Solve grid-based graph problems including flood fill, number of islands, shortest path in binary matrix, and surrounded regions with Python.
·11 min read · #dsa#graphs#intermediate
Graph Cycle Detection: DFS, Coloring, and Union-Find
Learn how to detect cycles in directed and undirected graphs using DFS with parent tracking, three-color DFS, and Union-Find with Python implementations.
·13 min read · #dsa#graphs#intermediate
Network Flow: Ford-Fulkerson and Edmonds-Karp
Understand max flow, residual graphs, augmenting paths, Ford-Fulkerson, Edmonds-Karp, and the max-flow min-cut theorem with Python code.
·12 min read · #dsa#graphs#advanced
Multi-Source BFS: Simultaneous Search from Multiple Starting Points
Master multi-source BFS for rotting oranges, walls and gates, 01-BFS, and matrix distance problems with Python implementations.
·11 min read · #dsa#graphs#intermediate
Shortest Path Algorithms: BFS, Dijkstra, Bellman-Ford, Floyd-Warshall
Compare all four shortest path algorithms with Python code, complexity analysis, and a decision flowchart for choosing the right one.
·12 min read · #dsa#graphs#intermediate
Strongly Connected Components: Kosaraju and Tarjan
Master SCCs with Kosaraju's two-pass DFS and Tarjan's low-link algorithm, including condensation graphs and real applications in Python.
·11 min read · #dsa#graphs#advanced
Topological Sort: Algorithms and Applications
Master topological sorting with Kahn's BFS and DFS approaches. Solve course scheduling, build dependencies, alien dictionary, and longest path in DAG problems.
·12 min read · #dsa#graphs#intermediate
Advanced Graph Algorithms: SCCs, Flows & Bridges
Deep dive into advanced graph algorithms — Tarjan's and Kosaraju's for SCCs, bridges and articulation points, Euler paths, network flow, and 2-SAT with real-world applications.
·11 min read · #dsa#graphs#advanced
Floyd-Warshall Algorithm for All-Pairs Shortest Paths
Master the Floyd-Warshall algorithm — understand the DP recurrence, implement it in Python, detect negative cycles, and know when to pick it over Dijkstra.
·4 min read · #dsa#graphs#intermediate
Graph Coloring and Bipartite Check
Learn graph coloring fundamentals — check if a graph is bipartite using BFS/DFS, solve m-coloring with backtracking, and tackle classic interview problems.
·5 min read · #dsa#graphs#intermediate
Graph Traversal Patterns: BFS, DFS, Topological Sort, and Shortest Path
Master graph traversal patterns for LeetCode including BFS, DFS, topological sort, Dijkstra, and practical templates with solutions.
·7 min read · #leetcode#graphs#bfs
Bellman-Ford and Negative-Weight Edges
Understand Bellman-Ford's relaxation loop, how it handles negative edges, detects negative cycles, and why it costs more than Dijkstra.
·5 min read · #graphs#shortest-path#intermediate
Dijkstra's Algorithm: Shortest Paths Explained
Learn Dijkstra's shortest path algorithm with a clean Python implementation, complexity analysis, and the priority queue intuition behind it.
·5 min read · #graphs#shortest-path#intermediate
Kruskal's and Prim's MST Algorithms
Build minimum spanning trees with Kruskal's union-find approach and Prim's priority queue approach, with side-by-side Python implementations.
·5 min read · #graphs#mst#intermediate
Clone Graph — DFS With a Node-to-Copy Hash Map
Why a hash map from original to copy is the entire idea, plus the BFS variant for stack-limited environments.
·5 min read · #dsa#leetcode#graphs
Course Schedule — Topological Sort With DFS
Detect cycles and produce a valid course order using DFS-based topological sort. Includes BFS Kahn alternative and interview script.
·6 min read · #dsa#leetcode#graphs
Pacific Atlantic Water Flow — Flood Inward From the Borders
Why reverse traversal beats per-cell flood fill, and how the intersection of two reach sets gives the answer.
·7 min read · #dsa#leetcode#graphs
Word Ladder — BFS Over Wildcard-Pattern Buckets
The wildcard-pattern adjacency trick, why BFS is mandatory, and the bidirectional speedup.
·6 min read · #dsa#leetcode#graphs
Topological Sort: Two Approaches Compared
Compare Kahn's BFS-based topological sort with DFS-based postorder, with Python implementations, complexity, and cycle detection.
·5 min read · #graphs#topological-sort#intermediate
Graph Traversals: BFS and DFS
A practical guide to BFS and DFS on graphs — recursive and iterative DFS, BFS with a deque, shortest paths on unweighted graphs, connected components, cycle detection, and five classic practice problems.
·11 min read · #dsa#graphs#intermediate
Graphs in DSA: Introduction and Representations
A practical introduction to graphs — directed vs undirected, weighted vs unweighted, cyclic vs acyclic, and the three main representations (adjacency list, adjacency matrix, edge list) with Python code.
·9 min read · #dsa#graphs#beginners