lec0502 - Welcom e! The Beauty of Computer Science Cinda...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Welcom e! The Beauty of Computer Science Cinda Heeren Lecturer Department of CS UIUC Let's play! 1. People on adjacent vertices must hold different poses. 2. Use the smallest # of poses possible. 3. I specify some poses. Graph Coloring Lunchroom Politics Suppose youofhave 16 friends each whose No one sitting at the same table can have the same talkitivity rating. No one sitting on the same side of a pair of tables can have the same talkitivity rating. talkitivity rating is O, L, P, S, 4 friends per type. Can you seat your friends? No one sitting in the same "column" can have the same talkitivity rating. Lunchroom Politics Suppose youofhave 16 friends each whose No one sitting at the same table can have the same talkitivity rating. No one sitting on the same side of a pair of tables can have the same talkitivity rating. talkitivity rating is O, L, P, S, 4 friends per type. Can you seat your friends? No one sitting in the same "column" can have the same talkitivity rating. Lunchroom Politics Fill in the grid so that each row, column, and bold 2x2 square has exactly one of each of the digits 1 through 4. Can you solve the puzzle? Sudoku Can you solve the puzzle? 3 2 2 1 4 Fill in the grid so that each row, column, and bold 2x2 square has exactly one of each of the digits 1 through 4. Sudoku? 3 2 2 1 4 Sudoku? 3 2 2 1 4 I can use my Graph Colorer to solve my Sudoku puzzles! To do so, I just have to run out to the store and buy an adapter that changes my Sudoku puzzle into the right graph... What does this have to do with computer science? You can think of the "adapter" and the "graph colorer" as pieces of software. They are programs whose inputs and outputs are well defined. Exam Map Color / Sudoku / / Scheduler Graph Graph Color Color ADAPTER ADAPTER ADAPTER Ultimate Graph Colorer Beautiful CS173 Graphs Suppose YOU are the person in charge of scheduling finals. Conflict exams are not allowed...that is, no student can have two exams scheduled for any one time. How many exam periods do you need? Why are these two problems on the same slide? Suppose I give you a graph consisting of vertices and edges. Your task is to label the vertices with colors. Vertices which share an edge cannot be colored the same. How many colors do you need? CS173 Graphs Graphs are a very general way of representing data. We can use graphs to model things as diverse as: Scheduling problems Routes for travelling between cities Connections between atoms in a molecule Paths that messages can take in a network Dependence relations between events in a large project CS173 Graphs CS173 Graphs Definitions you should understand: Simple Vertex Edge Weights Degree Neighbors Connected Complete Bipartite Planar Cycle Tree Path Circuit CS 173 Announcements Homework #13 available, due 5/7, 8a. Final exam 5/10, 710p, 1404 Siebel, email cinda w conflicts. Exam review: 5/9, 56:30p, location TBA Section this week is review. ...
View Full Document

Ask a homework question - tutors are online