DSA

Graph Algorithms

Master complex graph problems: Dijkstra's for shortest paths, Topological Sort for dependencies, and Cycle Detection.

By TechCoder TeamLast updated: 2026-06-02
In a Nutshell

Master complex graph problems: Dijkstra's for shortest paths, Topological Sort for dependencies, and Cycle Detection. This hands-on tutorial focuses on practical implementation of graph algorithms concepts.

Graph Algorithms

Beyond simple traversal, graphs are used to solve complex real-world problems like GPS routing and task scheduling.

1. Dijkstra's Algorithm (Shortest Path)

Finds the shortest path from a starting node to all other nodes in a weighted graph with non-negative weights.

Shortest A to B: A -> C -> B (Cost: 3)

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2. Topological Sort

Used for ordering nodes in a Directed Acyclic Graph (DAG) where some nodes must come before others (e.g., course prerequisites).

3. Cycle Detection

Determining if a graph contains a closed loop is critical for preventing infinite loops in systems.

  • Undirected: Use BFS/DFS (check if neighbor is visited and NOT the parent).
  • Directed: Use DFS (check if node is in the current recursion stack).

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Quiz

Quiz

Question 1 of 2

Which algorithm is most suitable for finding the shortest path in a weighted graph?

BFS
DFS
Dijkstra
Topological Sort