Graph Theory: Traveling Salesman Problem (TSP) E 3 Teacher Summer Research Program 2005 Texas A & M University June 29, 2005
TAKS Objectives 9 th & 10 th Grade Objective 1 – Ab1A, B, C, D & E Objective 2 – Ab2A & D, Ab3A & B Objective 3 – Ac1A & C Objective 6 – 8.7D Objective A, B & C, 8.15A, 8.16A & B
Material GEO Board Yarn Rubber bands Colored pencils Grid paper Graphing calculator
Vocabulary Nodes (vertices) Edges (arcs) Degree Adjacent Path
Vocabulary Length Circuit Simple Graph Complete Graph
Nodes (vertices)
Land Phone numbers People Junction points (electric circuits) Atom Chess players Companies or industries
Edges (arcs)
Bridges connecting land Calls made from one number to another connecting phone numbers Relationships or acquaintances connecting by people Wires connecting junction points (electric circuits) Bonds between atoms connecting atoms Matches connecting chess players (chess tournament) Transactions connecting companies or industries
Degree A F H G B E D C
Node A is of two degrees Node B is of two degrees Node C is of six degrees Node D is of three degrees How many degrees are nodes E, F, G and H?
Adjacent A F H G B E D C
Node A is adjacent to Nodes C and H Node B is adjacent to Nodes F and H Node C is adjacent to Nodes A, D, E, F, G and H Node D is adjacent to Nodes C, E and H What nodes are adjacent to nodes E, F, G and H?
Path A B C D E F
A B C D E F
A B C D E F
No Path A B C D E F
Draw two different paths. A B C D E F
Length A B C D E F
A B C D E F
A B C D E F
A B C D E F
Circuit Point A is the starting point C B D AE
C B D AE
C B D AE
C B D A E
Simple Graphs
Not, Simple Graphs
Complete Graphs
Draw a complete graph with six nodes. Draw a complete graph with seven nodes
Petroleum Delivers S T N M C T Texas S South Carolina N New York M Minnesota C Colorado
1 Node
2 Nodes
3 Nodes
2 Routes
4 Nodes
6 Routes
2 Node Node(s) Process Column Route(s) 21
3 Nodes Nodes Process Column Route(s) 32 21
4 Nodes Nodes Process Column Route(s)
2 Nodes Node(s) Process Column Route(s) 22-11
3 Nodes Nodes Process Column Route(s)
3 Nodes Nodes Process Column Route(s)
4 Nodes Nodes Process Column Route(s) nr1r1
4 Nodes Nodes Process Column Route(s) nr1r1
4 Nodes Nodes Process Column Route(s) nr1r1
4 Nodes Nodes Process Column Route(s) nn-1r1r1
Function Rule r 1 equals number of routes from each remaining nodes r 1 = n - 1
4 Nodes 3 2 1
Total Original Routes 4 Nodes 3 Routes Routes Route
Total Original Routes 3 x 2 x 1 = 6 or (4-1)!=6
Function Rule r 2 equals number of unique routes
Petroleum Delivers S T N M C T Texas S South Carolina N New York M Minnesota C Colorado