Key Concepts
Paths
Circuits
Euler circuits
ETC
100

Vertex Set

List of vertices in a graph.

100

A sequence of adjacent edges, where the edges are used only once.

Path

100
 A path that starts and ends at the same vertex.

Circuit

100

A graph with 8 vertices has an Euler Circuit. What can you say about the degree of each vertex. 

Each vertex must have an even degree.

100

Problems concerned with routing the delivery of goods or services to a set of destinations.

Routing problem

200

Edge list

List of edges in a graph.

200

The number of edges in a path.

length

200

A path in a connected graph that passes that starts and ends at the same vertex, and passes through  every edge of the graph one and only once.

Euler Circuit

200

A graph with 9 vertices has an Euler path but no Euler Circuit. The graph mus have 

2 vertices of odd degree and 7 vertices of even degree.

200

Problems where a specific set of connections (roads,  bridges, edges) must me traveled at least once. 

Street-routing problem

300

A vertex with degree zero.

Isolated vertex

300

A graph in which a path exists between any two vertices 

Connected graph

300

Will a complete graph of 3 vertices have an Euler Circuit? Yes or No.

Yes

300

A graph has an Euler path but no Euler circuit.  There are 25 vertices in the graph.  The graph must have...

2 vertices of odd degree and 23 vertices of even degrees. 

300

An edge that connects a vertex with itself

loop

400

Two vertices sharing the same edge

adjacent vertices

400

Connected parts of a graph

components

400

Will a complete graph with 4 vertices have an Euler Circuit?  Yes or no?

No

400

For a graph to have an Euler Path it must have 4 odd  vertices.  True or False 

False

400

Two or more edges connecting the two vertices

multiple-edges

500

An edge that connects a vertex with itself.

loop

500

A path in a connected graph that passes through every edge of the graph once and only once. 

Euler path

500

How do you know if a graph has an Euler Circuit?

If all vertices have even degrees.

500

The process of duplicating edges in a graph to make it have all but even vertices. 

Eulerization 

500

Number of edges meeting at the vertex

degree