Graphs and Euler's Circuit
Presentation with Sub-topic and Video | Due Next Week
Instructions Overview
• 1. Topic: Graphs and Euler's Circuit
• 2. Research beyond the blackboard
• 3. Choose your own sub-topic related to the
main topic
• 4. Prepare a video related to the topic
• 5. Present next week
Chosen Sub-topic: Euler Paths vs Euler Circuits
• Euler Path: A path that uses every edge of a graph exactly once.
• Euler Circuit: A circuit that uses every edge of
a graph exactly once and starts and ends at
the same vertex.
• We'll compare these two and explore when
each exists.
Examples and Explanation
• Example of Euler Path:
• - A graph with exactly two vertices of odd
degree.
• Example of Euler Circuit:
• - A graph where all vertices have even
degrees.
• We'll use visual aids and simple graphs to
show these.
Sample Graph
Video Resource
• Watch this video to understand Euler Circuits and Paths in depth:
• https://www.youtube.com/watch?v=GqX3r-
DUdlY
Sample Graph
Reminder
• Make sure to:
• - Understand the topic and sub-topic clearly
• - Watch the video linked in the previous slide
• - Prepare your part and be ready to present
next week!
What is a Graph?
• A graph is a set of vertices (nodes) connected by edges (lines). Graphs can
represent networks like roads, social connections, or circuits.
Types of Graphs
• 1. Undirected Graph
• 2. Directed Graph
• 3. Weighted Graph
• 4. Unweighted Graph
Degree of a Vertex
• The degree of a vertex is the number of edges connected to it. Vertices with even
or odd degrees determine the existence of Euler paths and circuits.
Sample Graph
Conditions for Euler Path
• An Euler Path exists in a graph if there are exactly two vertices with odd degrees.
Sample Graph
Conditions for Euler Circuit
• An Euler Circuit exists if all vertices have even degrees.
Sample Graph
Real-Life Example: Bridges of Königsberg
• Euler studied the problem of walking through all seven bridges of Königsberg
without repeating a bridge. He proved it was impossible, founding graph theory.
Graph Representation
• Graphs can be represented by:
• 1. Adjacency Matrix
• 2. Adjacency List
Euler Path Example 1
• Graph with vertices A, B, C, D where A and D have odd degrees — has Euler Path.
Euler Circuit Example 1
• Graph where all vertices have even degrees — has Euler Circuit starting and ending
at the same vertex.
How to Identify an Euler Path
• 1. Count the degree of each vertex.
• 2. If exactly two vertices have odd degrees, it's
an Euler Path.
How to Identify an Euler Circuit
• 1. Count the degree of each vertex.
• 2. If all vertices have even degrees, it's an
Euler Circuit. Sample Graph
Eulerization
• Eulerization is the process of adding edges to a graph to make it Eulerian.
Sample Graph
Hamiltonian vs Eulerian
• Eulerian Path uses every edge once.
• Hamiltonian Path visits every vertex once.
Directed Graphs and Euler Circuits
• In directed graphs, Euler circuits exist if the in-degree equals out-degree for all
vertices.
Why Learn Euler Circuits?
• Euler circuits are used in planning, optimization, and solving routing problems like
snow plow routes and garbage collection.
Quiz: Identify the Type
• Given a graph with vertex degrees: A(2), B(2), C(2), D(2) — Does it have an Euler
Circuit or Path?
• Answer: Euler Circuit.
Practice Problem
• Draw a graph with 4 vertices that has an Euler Path but not an Euler Circuit.
Review and Recap
• We've covered: Graph basics, Euler paths vs circuits, examples, conditions, real-life
applications, and practice questions.

Graphs_Euler_Circuit_Final_Presentation.pptx

  • 1.
    Graphs and Euler'sCircuit Presentation with Sub-topic and Video | Due Next Week
  • 2.
    Instructions Overview • 1.Topic: Graphs and Euler's Circuit • 2. Research beyond the blackboard • 3. Choose your own sub-topic related to the main topic • 4. Prepare a video related to the topic • 5. Present next week
  • 3.
    Chosen Sub-topic: EulerPaths vs Euler Circuits • Euler Path: A path that uses every edge of a graph exactly once. • Euler Circuit: A circuit that uses every edge of a graph exactly once and starts and ends at the same vertex. • We'll compare these two and explore when each exists.
  • 4.
    Examples and Explanation •Example of Euler Path: • - A graph with exactly two vertices of odd degree. • Example of Euler Circuit: • - A graph where all vertices have even degrees. • We'll use visual aids and simple graphs to show these. Sample Graph
  • 5.
    Video Resource • Watchthis video to understand Euler Circuits and Paths in depth: • https://www.youtube.com/watch?v=GqX3r- DUdlY Sample Graph
  • 6.
    Reminder • Make sureto: • - Understand the topic and sub-topic clearly • - Watch the video linked in the previous slide • - Prepare your part and be ready to present next week!
  • 7.
    What is aGraph? • A graph is a set of vertices (nodes) connected by edges (lines). Graphs can represent networks like roads, social connections, or circuits.
  • 8.
    Types of Graphs •1. Undirected Graph • 2. Directed Graph • 3. Weighted Graph • 4. Unweighted Graph
  • 9.
    Degree of aVertex • The degree of a vertex is the number of edges connected to it. Vertices with even or odd degrees determine the existence of Euler paths and circuits. Sample Graph
  • 10.
    Conditions for EulerPath • An Euler Path exists in a graph if there are exactly two vertices with odd degrees. Sample Graph
  • 11.
    Conditions for EulerCircuit • An Euler Circuit exists if all vertices have even degrees. Sample Graph
  • 12.
    Real-Life Example: Bridgesof Königsberg • Euler studied the problem of walking through all seven bridges of Königsberg without repeating a bridge. He proved it was impossible, founding graph theory.
  • 13.
    Graph Representation • Graphscan be represented by: • 1. Adjacency Matrix • 2. Adjacency List
  • 14.
    Euler Path Example1 • Graph with vertices A, B, C, D where A and D have odd degrees — has Euler Path.
  • 15.
    Euler Circuit Example1 • Graph where all vertices have even degrees — has Euler Circuit starting and ending at the same vertex.
  • 16.
    How to Identifyan Euler Path • 1. Count the degree of each vertex. • 2. If exactly two vertices have odd degrees, it's an Euler Path.
  • 17.
    How to Identifyan Euler Circuit • 1. Count the degree of each vertex. • 2. If all vertices have even degrees, it's an Euler Circuit. Sample Graph
  • 18.
    Eulerization • Eulerization isthe process of adding edges to a graph to make it Eulerian. Sample Graph
  • 19.
    Hamiltonian vs Eulerian •Eulerian Path uses every edge once. • Hamiltonian Path visits every vertex once.
  • 20.
    Directed Graphs andEuler Circuits • In directed graphs, Euler circuits exist if the in-degree equals out-degree for all vertices.
  • 21.
    Why Learn EulerCircuits? • Euler circuits are used in planning, optimization, and solving routing problems like snow plow routes and garbage collection.
  • 22.
    Quiz: Identify theType • Given a graph with vertex degrees: A(2), B(2), C(2), D(2) — Does it have an Euler Circuit or Path? • Answer: Euler Circuit.
  • 23.
    Practice Problem • Drawa graph with 4 vertices that has an Euler Path but not an Euler Circuit.
  • 24.
    Review and Recap •We've covered: Graph basics, Euler paths vs circuits, examples, conditions, real-life applications, and practice questions.