Math Problem Statement

Find two Euler trails in each graph using Fleury's algorithm.

Solution

To find two Euler trails in each graph (Q, R, and S) using Fleury's algorithm, we need to first understand the algorithm and analyze each graph.

Fleury's Algorithm Summary:

  1. Identify vertices with odd degree: Euler trails exist if exactly two vertices have odd degrees. A graph with all even-degree vertices will have an Euler circuit, and a graph with more than two odd vertices has no Euler trail.
  2. Start at an odd-degree vertex: If two odd vertices exist, start at one of them.
  3. Follow edges carefully: Use each edge once, and only remove an edge if it doesn't disconnect the remaining graph (i.e., don’t leave the graph disconnected unless it’s the final edge).

Let’s analyze each graph.

Graph Q

  • Vertices: {a, b, c, d, e, f, g}
  • Vertex degrees:
    • a: 2, b: 2, c: 3, d: 2, e: 3, f: 2, g: 2
    • Odd vertices: c, e
  • Conclusion: Euler trail is possible starting from either c or e.

Graph R

  • Vertices: {h, i, j, k, l, m}
  • Vertex degrees:
    • h: 2, i: 3, j: 2, k: 3, l: 2, m: 2
    • Odd vertices: i, k
  • Conclusion: Euler trail is possible starting from either i or k.

Graph S

  • Vertices: {n, o, p, q, r}
  • Vertex degrees:
    • n: 2, o: 3, p: 4, q: 3, r: 2
    • Odd vertices: o, q
  • Conclusion: Euler trail is possible starting from either o or q.

Finding Two Euler Trails:

For each graph, we will use Fleury’s algorithm and provide two trails, starting at each of the odd-degree vertices.


Graph Q (Start at c or e)

  • Trail 1 (Starting at c): c → d → e → f → g → e → a → b → c
  • Trail 2 (Starting at e): e → d → c → b → a → e → f → g → e

Graph R (Start at i or k)

  • Trail 1 (Starting at i): i → h → j → i → k → l → m → k
  • Trail 2 (Starting at k): k → l → m → k → i → h → j → i

Graph S (Start at o or q)

  • Trail 1 (Starting at o): o → n → p → o → q → r → p
  • Trail 2 (Starting at q): q → r → p → q → o → n → p

Would you like further explanations of any of the steps, or details about specific trails? Here are five related questions for you to consider:

  1. How does Fleury’s algorithm ensure that the graph remains connected during traversal?
  2. Can you identify a situation where Fleury's algorithm fails?
  3. How do Euler circuits differ from Euler trails?
  4. What are the conditions required for a graph to have an Euler circuit instead of a trail?
  5. How would you adjust Fleury’s algorithm for a weighted graph?

Tip: Remember that Euler trails are all about visiting each edge exactly once, but the starting and ending points can differ, especially when the graph has vertices of odd degree.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Graph Theory

Formulas

-

Theorems

Eulerian Path
Fleury's Algorithm

Suitable Grade Level

Advanced High School