Institute of Operating Systems and Computer Networks Algorithms Group. Network Algorithms. Tutorial 1: Flashback and Fast Forward
|
|
- Toby Riley
- 5 years ago
- Views:
Transcription
1 Institute of Operating Systems and Computer Networks Algorithms Group Network Algorithms Tutorial 1: Flashback and Fast Forward Christian Rieck
2 Staff Lecture: Dr. Christian Scheffer Room: IZ 331 Tutorial: Christian Rieck Room: IZ 314 Small tutorial: Jakob Keller 2
3 Structure Lecture: theoretical content on graph algorithms Tutorial: application of graph algorithms and many more cool stuff on graphs and problems on graphs Small tutorial: discussion of homework sheets 3
4 Homework and exam There will be five homework assignment sheets. You have to get at least 50% of the points in total. (Probably 150 out of 300.) You have to pass a written exam at the end of the lecture August, 6th. (Probably at 12am.) 4
5 Extra points You can earn extra points for your homework! find a (crucial) mistake in the slides improve the tutorial by a better example improve the tutorial by ideas on new interesting stuff Please send an or talk to me and I will think about it. Usually the amount of extra points is in some way related to the improvement and is a fraction of my room number π. 5
6 Mailing list There is a mailing list for this lecture. We will distribute several announcements via this list. So, please subscribe. 6
7 Webpage There is a webpage for this lecture. There is all the stuff like the slides of the tutorials, the homework assignment sheets, the schedule of the lecture, informations regarding the exam, 7
8 (preliminary) Schedule 8
9 (preliminary) Schedule There is also a calendar on the webpage which will be up-to-date! 8
10 Questions? 9
11 Previously in * 10
12 Graphs A graph is an ordered pair G=(V,E) comprising a set V of vertices together with a set E of edges, which are 2-element subsets of V. We normally consider simple graphs, i.e., there is at most one edge between two specific vertices and there are no edges connecting a vertex with itself. 11
13 Digraphs A digraph is an ordered pair D=(V,A) comprising a set V of vertices together with a set A of arcs (edges), which are ordered pairs of vertices. 12
14 Data structures for graphs There are several ways to represent graphs, e.g., adjacency list adjacency matrix incidence matrix Please make yourself familiar with these data structures. A good reference is the lecture on algorithms and data structures
15 Other data structures Stack last in, first out (LIFO) push pop Queue first in, first out (FIFO) enqueue dequeue 14
16 Breadth-First-Search procedure BFS(G,v) let Q be a queue Q.enqueue(v) while Q is not empty v = Q.dequeue() for each edge e incident to v let w be the other endpoint of e if w is not marked mark w Q.enqueue(w) v 0 v 0 v 1 v 2 v 3 v 4 v 1 v 2 v 3 v 5 v 6 v 7 v 8 v 5 v 6 v 7 v 10 v 9 v 10 v 9 v 11 v 12 v 11 v 4 v 8 v 12 15
17 Depth-First-Search procedure DFS(G,v) let S be a stack S.push(v) while S is not empty v = S.pop() if v is not labeled as discovered label v as discovered for all edges from v to w S.push(w) v 0 v 0 v 1 v 2 v 3 v 4 v 1 v 2 v 3 v 5 v 6 v 7 v 8 v 5 v 10 v 9 v 10 v 11 v 12 v 11 v 6 v 7 v 9 v 4 v 8 v 12 16
18 Walk, path, trail, Kantenfolge: Weg: Pfad: Tour: Kreis: Alternating sequence of vertices and edges. Kantenfolge + no repeating edges Kantenfolge + no repeating vertices Weg + same start and end vertex Pfad + same start and end vertex 17
19 Big O-Notation describes the limiting behavior of a function when the argument tends towards infinity is used to classify algorithms according to their running time (and other stuff ) O( f )={g : N! R + 9c 2 R >0 9n 0 2 N 8n 2 N n0 : g(n) apple c f (n)} g(n) 2 O( f (n)) f (n) g(n) n 0 18
20 Other Landau symbols There are some other notations for analyzing the running time and space requirements of algorithms, e.g., big-omega, Theta, Please make yourself familiar with these notations. Lecture on algorithms and data structures: Theta Lecture on algorithms and data structures: Big-O and Big-Omega 19
21 Proofs Well Sometimes it is very challenging to prove something. There are different methods, e.g., induction, or contraposition. Not only in this class you have to prove mathematical statements. Therefore you should be familiar with these methods and techniques
22 Proofs Well Sometimes it is very challenging to prove something. There are different methods, e.g., induction, or contraposition. Not only in this class you have to prove mathematical statements. Therefore you should be familiar with these methods and techniques
23 Different issues Eulerian Tour this is a problem! Given: A graph G Wanted: A tour that visits every edge exactly once Fleury s algorithm! Given: this is a specific instance! Wanted: A tour that visits every edge exactly once specific solution! 21
24 Different issues Hamiltonian Circle Given: A graph G Wanted: A circle that visits every vertex exactly once Traveling Salesman Tour Given: A weighted graph G Wanted: A circle of minimum total weight that visits every vertex exactly once Decision problem Given: A graph ( ) Wanted: A specific structure or an argument that such a structure do not exist in that graph Optimization problem Given: A graph ( ) and edge weights Wanted: From all feasible specific structures the best or an argument that such a structure do not exist in that graph 22
25 Soon in network algorithms 23
26 Minimum-cost problems Minimum Spanning Tree Given: A graph G=(V,E) with edge weights Wanted: A tree T of minimum cost that spans the graph G T 24
27 Minimum-cost problems Minimum Spanning Tree Given: A graph G=(V,E) with edge weights A geometric generalization is the Minimum Steiner Tree Problem. Wanted: A tree T of minimum cost that spans the graph One can also ask for a spanning tree where the longest edge is as short as possible the Minimum Bottleneck Spanning Tree! Or we want a minimum spanning tree where each vertex degree 7 6 is bounded by some value (Bounded Degree 5 Spanning Tree), or satisfies some other constraints Some 3 of them are really hard, e.g., most Steiner problems G T 24
28 Shortest-path problems Single source shortest paths Given: A graph G=(V,E) with edge weights, and a vertex s Wanted: A shortest path tree T rooted in s s G T 25
29 Shortest-path problems Single source shortest paths Given: A graph G=(V,E) with edge weights, and a vertex s Wanted: A shortest path tree T rooted in s There are many 7 related problems, e.g., Longest Path, Hamiltonian Path, several tour problems like the Traveling Salesman Problem, Almost all of them are NP-hard! s G T 25
30 Flows Maximum Flow Given: A digraph D=(V,A) with edge weights, and vertices s and t Wanted: A maximum flow F starting from s to t s t 6 1 D F 26
31 Flows Maximum Flow Given: A digraph D=(V,A) with edge weights, and vertices s and t Wanted: A maximum flow F starting from s to t A fundamental theorem is the MaxFlow-MinCut-Theorem of Ford and Fulkerson that shows that a maximum flow is equal to 7 a minimum 6 cut of a flow network t 5 There are polynomial-time algorithms for solving such flow problems. 11 But there are many related problems, and s 9some 9 of them are NP-hard D F 26
32 Matchings Maximum Matching Given: A graph G=(V,E) Wanted: A maximum set M of pairwise non-adjacent edges G M 27
33 Matchings Maximum Matching Given: A graph G=(V,E) Wanted: A maximum set M of pairwise non-adjacent edges There are many different variants of the matching problem, e.g., Perfect Matching, Minimum Cost Perfect Matching, Maximal Matching, Matching in bipartite Graphs, G M 27
34 Questions? 28
Introduction to Graph Theory
Introduction to Graph Theory Tandy Warnow January 20, 2017 Graphs Tandy Warnow Graphs A graph G = (V, E) is an object that contains a vertex set V and an edge set E. We also write V (G) to denote the vertex
More informationInstitute of Operating Systems and Computer Networks Algorithms Group. Network Algorithms. Tutorial 4: Matching and other stuff
Institute of Operating Systems and Computer Networks Algorithms Group Network Algorithms Tutorial 4: Matching and other stuff Christian Rieck Matching 2 Matching A matching M in a graph is a set of pairwise
More informationData Structure. IBPS SO (IT- Officer) Exam 2017
Data Structure IBPS SO (IT- Officer) Exam 2017 Data Structure: In computer science, a data structure is a way of storing and organizing data in a computer s memory so that it can be used efficiently. Data
More informationDesign and Analysis of Algorithms
CS4335: Design and Analysis of Algorithms Who we are: Dr. Lusheng WANG Dept. of Computer Science office: B6422 phone: 2788 9820 e-mail: lwang@cs.cityu.edu.hk Course web site: http://www.cs.cityu.edu.hk/~lwang/ccs3335.html
More informationimplementing the breadth-first search algorithm implementing the depth-first search algorithm
Graph Traversals 1 Graph Traversals representing graphs adjacency matrices and adjacency lists 2 Implementing the Breadth-First and Depth-First Search Algorithms implementing the breadth-first search algorithm
More informationGraphs and Algorithms 2016
Graphs and Algorithms 2016 Teachers: Nikhil Bansal and Jesper Nederlof TA: Shashwat Garg (Office Hours: Thursday: Pick??) Webpage: www.win.tue.nl/~nikhil/courses/2wo08 (for up to date information, links
More informationChapter 9 Graph Algorithms
Introduction graph theory useful in practice represent many real-life problems can be if not careful with data structures Chapter 9 Graph s 2 Definitions Definitions an undirected graph is a finite set
More informationval(y, I) α (9.0.2) α (9.0.3)
CS787: Advanced Algorithms Lecture 9: Approximation Algorithms In this lecture we will discuss some NP-complete optimization problems and give algorithms for solving them that produce a nearly optimal,
More informationLet G = (V, E) be a graph. If u, v V, then u is adjacent to v if {u, v} E. We also use the notation u v to denote that u is adjacent to v.
Graph Adjacent Endpoint of an edge Incident Neighbors of a vertex Degree of a vertex Theorem Graph relation Order of a graph Size of a graph Maximum and minimum degree Let G = (V, E) be a graph. If u,
More informationChapter 9 Graph Algorithms
Chapter 9 Graph Algorithms 2 Introduction graph theory useful in practice represent many real-life problems can be if not careful with data structures 3 Definitions an undirected graph G = (V, E) is a
More informationAdjacent: Two distinct vertices u, v are adjacent if there is an edge with ends u, v. In this case we let uv denote such an edge.
1 Graph Basics What is a graph? Graph: a graph G consists of a set of vertices, denoted V (G), a set of edges, denoted E(G), and a relation called incidence so that each edge is incident with either one
More informationChapter 9 Graph Algorithms
Chapter 9 Graph Algorithms 2 Introduction graph theory useful in practice represent many real-life problems can be slow if not careful with data structures 3 Definitions an undirected graph G = (V, E)
More informationr=1 The Binomial Theorem. 4 MA095/98G Revision
Revision Read through the whole course once Make summary sheets of important definitions and results, you can use the following pages as a start and fill in more yourself Do all assignments again Do the
More information11/22/2016. Chapter 9 Graph Algorithms. Introduction. Definitions. Definitions. Definitions. Definitions
Introduction Chapter 9 Graph Algorithms graph theory useful in practice represent many real-life problems can be slow if not careful with data structures 2 Definitions an undirected graph G = (V, E) is
More informationLecture 3: Graphs and flows
Chapter 3 Lecture 3: Graphs and flows Graphs: a useful combinatorial structure. Definitions: graph, directed and undirected graph, edge as ordered pair, path, cycle, connected graph, strongly connected
More informationSome major graph problems
CS : Graphs and Blobs! Prof. Graeme Bailey http://cs.cs.cornell.edu (notes modified from Noah Snavely, Spring 009) Some major graph problems! Graph colouring Ensuring that radio stations don t clash! Graph
More informationGraph Algorithms. Chapter 22. CPTR 430 Algorithms Graph Algorithms 1
Graph Algorithms Chapter 22 CPTR 430 Algorithms Graph Algorithms Why Study Graph Algorithms? Mathematical graphs seem to be relatively specialized and abstract Why spend so much time and effort on algorithms
More informationAbout the Author. Dependency Chart. Chapter 1: Logic and Sets 1. Chapter 2: Relations and Functions, Boolean Algebra, and Circuit Design
Preface About the Author Dependency Chart xiii xix xxi Chapter 1: Logic and Sets 1 1.1: Logical Operators: Statements and Truth Values, Negations, Conjunctions, and Disjunctions, Truth Tables, Conditional
More informationCMPSCI611: The SUBSET-SUM Problem Lecture 18
CMPSCI611: The SUBSET-SUM Problem Lecture 18 We begin today with the problem we didn t get to at the end of last lecture the SUBSET-SUM problem, which we also saw back in Lecture 8. The input to SUBSET-
More information1 Variations of the Traveling Salesman Problem
Stanford University CS26: Optimization Handout 3 Luca Trevisan January, 20 Lecture 3 In which we prove the equivalence of three versions of the Traveling Salesman Problem, we provide a 2-approximate algorithm,
More informationCOMP Analysis of Algorithms & Data Structures
COMP 3170 - Analysis of Algorithms & Data Structures Shahin Kamali Approximation Algorithms CLRS 35.1-35.5 University of Manitoba COMP 3170 - Analysis of Algorithms & Data Structures 1 / 30 Approaching
More informationMathematics and Statistics, Part A: Graph Theory Problem Sheet 1, lectures 1-4
1. Draw Mathematics and Statistics, Part A: Graph Theory Problem Sheet 1, lectures 1-4 (i) a simple graph. A simple graph has a non-empty vertex set and no duplicated edges. For example sketch G with V
More informationSolving problems on graph algorithms
Solving problems on graph algorithms Workshop Organized by: ACM Unit, Indian Statistical Institute, Kolkata. Tutorial-3 Date: 06.07.2017 Let G = (V, E) be an undirected graph. For a vertex v V, G {v} is
More informationI A graph is a mathematical structure consisting of a set of. I Formally: G =(V, E), where V is a set and E V V.
Directed and Undirected Graphs Inf 2B: Graphs, BFS, DFS Kyriakos Kalorkoti School of Informatics University of Edinburgh I A graph is a mathematical structure consisting of a set of vertices and a set
More informationChapter 5 Graph Algorithms Algorithm Theory WS 2012/13 Fabian Kuhn
Chapter 5 Graph Algorithms Algorithm Theory WS 2012/13 Fabian Kuhn Graphs Extremely important concept in computer science Graph, : node (or vertex) set : edge set Simple graph: no self loops, no multiple
More informationGraphs and Network Flows IE411. Lecture 13. Dr. Ted Ralphs
Graphs and Network Flows IE411 Lecture 13 Dr. Ted Ralphs IE411 Lecture 13 1 References for Today s Lecture IE411 Lecture 13 2 References for Today s Lecture Required reading Sections 21.1 21.2 References
More informationDESIGN AND ANALYSIS OF ALGORITHMS
DESIGN AND ANALYSIS OF ALGORITHMS QUESTION BANK Module 1 OBJECTIVE: Algorithms play the central role in both the science and the practice of computing. There are compelling reasons to study algorithms.
More informationPATH FINDING AND GRAPH TRAVERSAL
GRAPH TRAVERSAL PATH FINDING AND GRAPH TRAVERSAL Path finding refers to determining the shortest path between two vertices in a graph. We discussed the Floyd Warshall algorithm previously, but you may
More informationGraph Theory S 1 I 2 I 1 S 2 I 1 I 2
Graph Theory S I I S S I I S Graphs Definition A graph G is a pair consisting of a vertex set V (G), and an edge set E(G) ( ) V (G). x and y are the endpoints of edge e = {x, y}. They are called adjacent
More informationThis course is intended for 3rd and/or 4th year undergraduate majors in Computer Science.
Lecture 9 Graphs This course is intended for 3rd and/or 4th year undergraduate majors in Computer Science. You need to be familiar with the design and use of basic data structures such as Lists, Stacks,
More informationFundamental Algorithms
Fundamental Algorithms Chapter 8: Graphs Jan Křetínský Winter 2017/18 Chapter 8: Graphs, Winter 2017/18 1 Graphs Definition (Graph) A graph G = (V, E) consists of a set V of vertices (nodes) and a set
More informationCLASS: II YEAR / IV SEMESTER CSE CS 6402-DESIGN AND ANALYSIS OF ALGORITHM UNIT I INTRODUCTION
CLASS: II YEAR / IV SEMESTER CSE CS 6402-DESIGN AND ANALYSIS OF ALGORITHM UNIT I INTRODUCTION 1. What is performance measurement? 2. What is an algorithm? 3. How the algorithm is good? 4. What are the
More informationCS2 Algorithms and Data Structures Note 9
CS2 Algorithms and Data Structures Note 9 Graphs The remaining three lectures of the Algorithms and Data Structures thread will be devoted to graph algorithms. 9.1 Directed and Undirected Graphs A graph
More informationInf 2B: Graphs, BFS, DFS
Inf 2B: Graphs, BFS, DFS Kyriakos Kalorkoti School of Informatics University of Edinburgh Directed and Undirected Graphs I A graph is a mathematical structure consisting of a set of vertices and a set
More informationEECS 203 Lecture 20. More Graphs
EECS 203 Lecture 20 More Graphs Admin stuffs Last homework due today Office hour changes starting Friday (also in Piazza) Friday 6/17: 2-5 Mark in his office. Sunday 6/19: 2-5 Jasmine in the UGLI. Monday
More informationLecture 26: Graphs: Traversal (Part 1)
CS8 Integrated Introduction to Computer Science Fisler, Nelson Lecture 6: Graphs: Traversal (Part ) 0:00 AM, Apr, 08 Contents Introduction. Definitions........................................... Representations.......................................
More informationAPPROXIMATION ALGORITHMS FOR GEOMETRIC PROBLEMS
APPROXIMATION ALGORITHMS FOR GEOMETRIC PROBLEMS Subhas C. Nandy (nandysc@isical.ac.in) Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata 70010, India. Organization Introduction
More informationIntroduction to Algorithms Third Edition
Thomas H. Cormen Charles E. Leiserson Ronald L. Rivest Clifford Stein Introduction to Algorithms Third Edition The MIT Press Cambridge, Massachusetts London, England Preface xiü I Foundations Introduction
More informationGraph Algorithms Using Depth First Search
Graph Algorithms Using Depth First Search Analysis of Algorithms Week 8, Lecture 1 Prepared by John Reif, Ph.D. Distinguished Professor of Computer Science Duke University Graph Algorithms Using Depth
More informationV1.0: Seth Gilbert, V1.1: Steven Halim August 30, Abstract. d(e), and we assume that the distance function is non-negative (i.e., d(x, y) 0).
CS4234: Optimisation Algorithms Lecture 4 TRAVELLING-SALESMAN-PROBLEM (4 variants) V1.0: Seth Gilbert, V1.1: Steven Halim August 30, 2016 Abstract The goal of the TRAVELLING-SALESMAN-PROBLEM is to find
More informationCMPSCI 311: Introduction to Algorithms Practice Final Exam
CMPSCI 311: Introduction to Algorithms Practice Final Exam Name: ID: Instructions: Answer the questions directly on the exam pages. Show all your work for each question. Providing more detail including
More informationGraphs and Algorithms 2015
Graphs and Algorithms 2015 Teachers: Nikhil Bansal and Jorn van der Pol Webpage: www.win.tue.nl/~nikhil/courses/2wo08 (for up to date information, links to reading material) Goal: Have fun with discrete
More informationInstant Insanity Instructor s Guide Make-it and Take-it Kit for AMTNYS 2006
Instant Insanity Instructor s Guide Make-it and Take-it Kit for AMTNYS 2006 THE KIT: This kit contains materials for two Instant Insanity games, a student activity sheet with answer key and this instructor
More informationI want an Oompa-Loompa! screamed Veruca. Roald Dahl, Charlie and the Chocolate Factory
Greedy and Basic Graph Algorithms CS 421 - Algorithms Spring 2019 Apr 5, 2019 Name: Collaborators: I want an Oompa-Loompa! screamed Veruca. Roald Dahl, Charlie and the Chocolate Factory This problem set
More informationSearch Algorithms. IE 496 Lecture 17
Search Algorithms IE 496 Lecture 17 Reading for This Lecture Primary Horowitz and Sahni, Chapter 8 Basic Search Algorithms Search Algorithms Search algorithms are fundamental techniques applied to solve
More informationPractice Final Exam 1
Algorithm esign Techniques Practice Final xam Instructions. The exam is hours long and contains 6 questions. Write your answers clearly. You may quote any result/theorem seen in the lectures or in the
More informationLECTURES 3 and 4: Flows and Matchings
LECTURES 3 and 4: Flows and Matchings 1 Max Flow MAX FLOW (SP). Instance: Directed graph N = (V,A), two nodes s,t V, and capacities on the arcs c : A R +. A flow is a set of numbers on the arcs such that
More informationMatching Theory. Figure 1: Is this graph bipartite?
Matching Theory 1 Introduction A matching M of a graph is a subset of E such that no two edges in M share a vertex; edges which have this property are called independent edges. A matching M is said to
More informationCS70 - Lecture 6. Graphs: Coloring; Special Graphs. 1. Review of L5 2. Planar Five Color Theorem 3. Special Graphs:
CS70 - Lecture 6 Graphs: Coloring; Special Graphs 1. Review of L5 2. Planar Five Color Theorem 3. Special Graphs: Trees: Three characterizations Hypercubes: Strongly connected! Administration You need
More informationMath 776 Graph Theory Lecture Note 1 Basic concepts
Math 776 Graph Theory Lecture Note 1 Basic concepts Lectured by Lincoln Lu Transcribed by Lincoln Lu Graph theory was founded by the great Swiss mathematician Leonhard Euler (1707-178) after he solved
More informationLecture 8: The Traveling Salesman Problem
Lecture 8: The Traveling Salesman Problem Let G = (V, E) be an undirected graph. A Hamiltonian cycle of G is a cycle that visits every vertex v V exactly once. Instead of Hamiltonian cycle, we sometimes
More information12/5/17. trees. CS 220: Discrete Structures and their Applications. Trees Chapter 11 in zybooks. rooted trees. rooted trees
trees CS 220: Discrete Structures and their Applications A tree is an undirected graph that is connected and has no cycles. Trees Chapter 11 in zybooks rooted trees Rooted trees. Given a tree T, choose
More informationPolynomial time approximation algorithms
Polynomial time approximation algorithms Doctoral course Optimization on graphs - Lecture 5.2 Giovanni Righini January 18 th, 2013 Approximation algorithms There are several reasons for using approximation
More informationCMSC 451: Lecture 22 Approximation Algorithms: Vertex Cover and TSP Tuesday, Dec 5, 2017
CMSC 451: Lecture 22 Approximation Algorithms: Vertex Cover and TSP Tuesday, Dec 5, 2017 Reading: Section 9.2 of DPV. Section 11.3 of KT presents a different approximation algorithm for Vertex Cover. Coping
More informationChapter 4. Relations & Graphs. 4.1 Relations. Exercises For each of the relations specified below:
Chapter 4 Relations & Graphs 4.1 Relations Definition: Let A and B be sets. A relation from A to B is a subset of A B. When we have a relation from A to A we often call it a relation on A. When we have
More informationApproximation Algorithms
15-251: Great Ideas in Theoretical Computer Science Spring 2019, Lecture 14 March 5, 2019 Approximation Algorithms 1 2 SAT 3SAT Clique Hamiltonian- Cycle given a Boolean formula F, is it satisfiable? same,
More informationGRAPHS Lecture 19 CS2110 Spring 2013
GRAPHS Lecture 19 CS2110 Spring 2013 Announcements 2 Prelim 2: Two and a half weeks from now Tuesday, April16, 7:30-9pm, Statler Exam conflicts? We need to hear about them and can arrange a makeup It would
More informationCSE 21 Spring 2016 Homework 5. Instructions
CSE 21 Spring 2016 Homework 5 Instructions Homework should be done in groups of one to three people. You are free to change group members at any time throughout the quarter. Problems should be solved together,
More informationGRAPHS: THEORY AND ALGORITHMS
GRAPHS: THEORY AND ALGORITHMS K. THULASIRAMAN M. N. S. SWAMY Concordia University Montreal, Canada A Wiley-Interscience Publication JOHN WILEY & SONS, INC. New York / Chichester / Brisbane / Toronto /
More informationCS 4407 Algorithms. Lecture 8: Circumventing Intractability, using Approximation and other Techniques
CS 4407 Algorithms Lecture 8: Circumventing Intractability, using Approximation and other Techniques Prof. Gregory Provan Department of Computer Science University College Cork CS 4010 1 Lecture Outline
More information6.856 Randomized Algorithms
6.856 Randomized Algorithms David Karger Handout #4, September 21, 2002 Homework 1 Solutions Problem 1 MR 1.8. (a) The min-cut algorithm given in class works because at each step it is very unlikely (probability
More information(Refer Slide Time: 01:00)
Advanced Operations Research Prof. G. Srinivasan Department of Management Studies Indian Institute of Technology, Madras Lecture minus 26 Heuristics for TSP In this lecture, we continue our discussion
More informationGraph and Digraph Glossary
1 of 15 31.1.2004 14:45 Graph and Digraph Glossary A B C D E F G H I-J K L M N O P-Q R S T U V W-Z Acyclic Graph A graph is acyclic if it contains no cycles. Adjacency Matrix A 0-1 square matrix whose
More informationTheorem 2.9: nearest addition algorithm
There are severe limits on our ability to compute near-optimal tours It is NP-complete to decide whether a given undirected =(,)has a Hamiltonian cycle An approximation algorithm for the TSP can be used
More informationReference Sheet for CO142.2 Discrete Mathematics II
Reference Sheet for CO14. Discrete Mathematics II Spring 017 1 Graphs Defintions 1. Graph: set of N nodes and A arcs such that each a A is associated with an unordered pair of nodes.. Simple graph: no
More informationcsci 210: Data Structures Graph Traversals
csci 210: Data Structures Graph Traversals Graph traversal (BFS and DFS) G can be undirected or directed We think about coloring each vertex WHITE before we start GRAY after we visit a vertex but before
More informationInformation Science 2
Information Science 2 - Applica(ons of Basic ata Structures- Week 03 College of Information Science and Engineering Ritsumeikan University Agenda l Week 02 review l Introduction to Graph Theory - Basic
More informationComputational Optimization ISE 407. Lecture 19. Dr. Ted Ralphs
Computational Optimization ISE 407 Lecture 19 Dr. Ted Ralphs ISE 407 Lecture 19 1 Search Algorithms Search algorithms are fundamental techniques applied to solve a wide range of optimization problems.
More informationLecture 24: More Reductions (1997) Steven Skiena. skiena
Lecture 24: More Reductions (1997) Steven Skiena Department of Computer Science State University of New York Stony Brook, NY 11794 4400 http://www.cs.sunysb.edu/ skiena Prove that subgraph isomorphism
More information4. (a) Draw the Petersen graph. (b) Use Kuratowski s teorem to prove that the Petersen graph is non-planar.
UPPSALA UNIVERSITET Matematiska institutionen Anders Johansson Graph Theory Frist, KandMa, IT 010 10 1 Problem sheet 4 Exam questions Solve a subset of, say, four questions to the problem session on friday.
More informationCS270 Combinatorial Algorithms & Data Structures Spring Lecture 19:
CS270 Combinatorial Algorithms & Data Structures Spring 2003 Lecture 19: 4.1.03 Lecturer: Satish Rao Scribes: Kevin Lacker and Bill Kramer Disclaimer: These notes have not been subjected to the usual scrutiny
More information- Logic and Algorithms - Graph Algorithms
Fundamentals of Computer Sience and Digital Communications - Logic and Algorithms - Graph Algorithms Johan Larsson Marco Loh 22..24 Overview What is a Graph? Representations of Graphs Breadth-first Search
More informationCS261: A Second Course in Algorithms Lecture #16: The Traveling Salesman Problem
CS61: A Second Course in Algorithms Lecture #16: The Traveling Salesman Problem Tim Roughgarden February 5, 016 1 The Traveling Salesman Problem (TSP) In this lecture we study a famous computational problem,
More informationDefinition For vertices u, v V (G), the distance from u to v, denoted d(u, v), in G is the length of a shortest u, v-path. 1
Graph fundamentals Bipartite graph characterization Lemma. If a graph contains an odd closed walk, then it contains an odd cycle. Proof strategy: Consider a shortest closed odd walk W. If W is not a cycle,
More informationINSTITUTE OF AERONAUTICAL ENGINEERING
INSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigal, Hyderabad -500 043 INFORMATION TECHNOLOGY TUTORIAL QUESTION BANK Course Name : DESIGN AND ANALYSIS OF ALGORITHMS Course Code : AIT001 Class
More information10/31/18. About A6, Prelim 2. Spanning Trees, greedy algorithms. Facts about trees. Undirected trees
//8 About A, Prelim Spanning Trees, greedy algorithms Lecture CS Fall 8 Prelim : Thursday, November. Visit exams page of course website and read carefully to find out when you take it (: or 7:) and what
More informationOutline. Introduction. Representations of Graphs Graph Traversals. Applications. Definitions and Basic Terminologies
Graph Chapter 9 Outline Introduction Definitions and Basic Terminologies Representations of Graphs Graph Traversals Breadth first traversal Depth first traversal Applications Single source shortest path
More informationSpanning Trees, greedy algorithms. Lecture 20 CS2110 Fall 2018
1 Spanning Trees, greedy algorithms Lecture 20 CS2110 Fall 2018 1 About A6, Prelim 2 Prelim 2: Thursday, 15 November. Visit exams page of course website and read carefully to find out when you take it
More informationPSD1A. DESIGN AND ANALYSIS OF ALGORITHMS Unit : I-V
PSD1A DESIGN AND ANALYSIS OF ALGORITHMS Unit : I-V UNIT I -- Introduction -- Definition of Algorithm -- Pseudocode conventions -- Recursive algorithms -- Time and space complexity -- Big- o notation --
More information12 Abstract Data Types
12 Abstract Data Types 12.1 Foundations of Computer Science Cengage Learning Objectives After studying this chapter, the student should be able to: Define the concept of an abstract data type (ADT). Define
More informationCourse Review. Cpt S 223 Fall 2009
Course Review Cpt S 223 Fall 2009 1 Final Exam When: Tuesday (12/15) 8-10am Where: in class Closed book, closed notes Comprehensive Material for preparation: Lecture slides & class notes Homeworks & program
More informationAnnouncements. CSEP 521 Applied Algorithms. Announcements. Polynomial time efficiency. Definitions of efficiency 1/14/2013
Announcements CSEP 51 Applied Algorithms Richard Anderson Winter 013 Lecture Reading Chapter.1,. Chapter 3 Chapter Homework Guidelines Prove that your algorithm works A proof is a convincing argument Give
More informationAlgorithms for Euclidean TSP
This week, paper [2] by Arora. See the slides for figures. See also http://www.cs.princeton.edu/~arora/pubs/arorageo.ps Algorithms for Introduction This lecture is about the polynomial time approximation
More informationCoping with NP-Completeness
Coping with NP-Completeness Siddhartha Sen Questions: sssix@cs.princeton.edu Some figures obtained from Introduction to Algorithms, nd ed., by CLRS Coping with intractability Many NPC problems are important
More informationLecture 8: PATHS, CYCLES AND CONNECTEDNESS
Discrete Mathematics August 20, 2014 Lecture 8: PATHS, CYCLES AND CONNECTEDNESS Instructor: Sushmita Ruj Scribe: Ishan Sahu & Arnab Biswas 1 Paths, Cycles and Connectedness 1.1 Paths and Cycles 1. Paths
More informationChapter 3: Paths and Cycles
Chapter 3: Paths and Cycles 5 Connectivity 1. Definitions: Walk: finite sequence of edges in which any two consecutive edges are adjacent or identical. (Initial vertex, Final vertex, length) Trail: walk
More informationSolutions for the Exam 6 January 2014
Mastermath and LNMB Course: Discrete Optimization Solutions for the Exam 6 January 2014 Utrecht University, Educatorium, 13:30 16:30 The examination lasts 3 hours. Grading will be done before January 20,
More informationTopics. Trees Vojislav Kecman. Which graphs are trees? Terminology. Terminology Trees as Models Some Tree Theorems Applications of Trees CMSC 302
Topics VCU, Department of Computer Science CMSC 302 Trees Vojislav Kecman Terminology Trees as Models Some Tree Theorems Applications of Trees Binary Search Tree Decision Tree Tree Traversal Spanning Trees
More informationVirtual University of Pakistan
Virtual University of Pakistan Department of Computer Science Course Outline Course Instructor Dr. Sohail Aslam E mail Course Code Course Title Credit Hours 3 Prerequisites Objectives Learning Outcomes
More informationNotes for Lecture 24
U.C. Berkeley CS170: Intro to CS Theory Handout N24 Professor Luca Trevisan December 4, 2001 Notes for Lecture 24 1 Some NP-complete Numerical Problems 1.1 Subset Sum The Subset Sum problem is defined
More information(Re)Introduction to Graphs and Some Algorithms
(Re)Introduction to Graphs and Some Algorithms Graph Terminology (I) A graph is defined by a set of vertices V and a set of edges E. The edge set must work over the defined vertices in the vertex set.
More informationOutline. Graphs. Divide and Conquer.
GRAPHS COMP 321 McGill University These slides are mainly compiled from the following resources. - Professor Jaehyun Park slides CS 97SI - Top-coder tutorials. - Programming Challenges books. Outline Graphs.
More informationProposition 1. The edges of an even graph can be split (partitioned) into cycles, no two of which have an edge in common.
Math 3116 Dr. Franz Rothe June 5, 2012 08SUM\3116_2012t1.tex Name: Use the back pages for extra space 1 Solution of Test 1.1 Eulerian graphs Proposition 1. The edges of an even graph can be split (partitioned)
More informationlecture27: Graph Traversals
lecture27: Largely based on slides by Cinda Heeren CS 225 UIUC 25th July, 2013 Announcements mp7.1 extra credit due tomorrow night (7/26) Code challenge tomorrow night (7/26) at 6pm in 0224 lab hash due
More informationHomework 3 Solutions
CS3510 Design & Analysis of Algorithms Section A Homework 3 Solutions Released: 7pm, Wednesday Nov 8, 2017 This homework has a total of 4 problems on 4 pages. Solutions should be submitted to GradeScope
More informationBranch and Bound. Live-node: A node that has not been expanded. It is similar to backtracking technique but uses BFS-like search.
Branch and Bound Definitions: Branch and Bound is a state space search method in which all the children of a node are generated before expanding any of its children. Live-node: A node that has not been
More informationMatching 4/21/2016. Bipartite Matching. 3330: Algorithms. First Try. Maximum Matching. Key Questions. Existence of Perfect Matching
Bipartite Matching Matching 3330: Algorithms A graph is bipartite if its vertex set can be partitioned into two subsets A and B so that each edge has one endpoint in A and the other endpoint in B. A B
More informationGraphs and Network Flows IE411. Lecture 21. Dr. Ted Ralphs
Graphs and Network Flows IE411 Lecture 21 Dr. Ted Ralphs IE411 Lecture 21 1 Combinatorial Optimization and Network Flows In general, most combinatorial optimization and integer programming problems are
More informationLecture Notes for IEOR 266: Graph Algorithms and Network Flows
Lecture Notes for IEOR 266: Graph Algorithms and Network Flows Professor Dorit S. Hochbaum Contents 1 Introduction 1 1.1 Assignment problem.................................... 1 1.2 Basic graph definitions...................................
More informationCS 310 Advanced Data Structures and Algorithms
CS 31 Advanced Data Structures and Algorithms Graphs July 18, 17 Tong Wang UMass Boston CS 31 July 18, 17 1 / 4 Graph Definitions Graph a mathematical construction that describes objects and relations
More information