Graph Theory (Quick Summary)

Data structure that represents relationships between points (Nodes) and lines (Edges)

1. Types of Graphs

• Directed Graph (Digraph): Graphs with directions (e.g., Followers on Twitter)
• Undirected Graph: Graphs without directions (e.g., Friends on Facebook)
• Weighted Graph: Graphs with weights on edges (e.g., Google Maps routes with distances)

2. Important Terminology

• Degree: Number of edges connected to that node
• Path: A sequence of connected nodes
• Cycle: A Path that starts and ends at the same node
• Connected Graph: A path exists between every pair of nodes

3. Trees

• A Tree is a connected Undirected Graph with no Cycle
• Branches out continuously from a Root Node (Used in Directory structures, DOM tree)

4. Applications

• Finding Shortest Paths
• Internet networks (Network Topology)
• Friend or product recommendation systems