C&O 351: Network Flows, Winter 2010

General Information

Course Website: http://www.math.uwaterloo.ca/~harvey/W10/

Lecture Time: Tuesdays & Thursdays, 11:30am-12:50pm

Lecture Room: RCH 208

Instructor: Professor Nicholas Harvey, MC 6068, harvey@math.uwaterloo.ca

·         Office Hours: Thursdays, 2:00-3:00pm

Teaching Assistant: David Roberson, DC 3144, droberson@uwaterloo.ca

·         Office Hours: Tuesdays, 1:30-2:30pm

 

Syllabus

 

Assignments

There will be about 5 assignments in this class. The questions are handed out in class, and also available below.

 

Handed out

Due date

Questions

Solutions

1.

1/14

1/21

HW1

Sol1

2.

1/26

2/4

HW2

Sol2

3.

2/4

2/11

HW3

Sol3

4.

3/2

3/11

HW4

Sol4

5.

3/18

3/30

HW5

Sol5

 

Lecture Schedule

 

Date

Topics

Relevant Reading

1.

1/5

Course Overview, Currency Exchange Example, Swiss Bank Example

Course Notes Section 2.1

2.

1/7

Longest Dipath, Knapsack Problem, Decomposition of Diwalks

Course Notes Section 1.2, 2.1.2, 2.2.1

3.

1/12

Potentials: Existence & relation to shortest diwalks

Course Notes Section 2.2.2

4.

1/14

Potentials. A linear program for shortest paths.

Course Notes Section 2.2.2, 2.2.3

5.

1/19

Potentials: String & nuts example. Dual of the shortest paths LP.

Course Notes Section 2.2.3

6.

1/21

Shortest path trees. Internet routing example. Dijkstra’s Algorithm.

Course Notes Section 2.2.5, 2.3

7.

1/26

Directed acyclic graphs: Topological Sort and Shortest Paths

Course Notes Section 2.4.1, 2.4.2

8.

1/28

Shortest paths in arbitrary digraphs: the Bellman-Ford Algorithm

Wikipedia, Demaine’s Lecture

Example Applet

9.

2/2

Maximum Flows: Definition, LP, Incrementing Paths

Course Notes Section 3, 3.1

10.

2/4

Residual Digraph, Ford-Fulkerson Algorithm, Max Flow <= Min Cut

Course Notes Section 3.3, 3.2

11.

2/9

Optimality conditions, Max Flow = Min Cut, Integral Flows

Course Notes Section 3.2, 3.3

12.

2/11

Bipartite Matching via Max Flow, Konig’s Theorem

Course Notes Section 3.6.3

13.

2/23

Midterm Exam. Solutions

 

14.

2/25

The Edmonds-Karp Algorithm

Course Notes Section 3.3.1

15.

3/2

Finish Edmonds-Karp. Optimal Closures.

Course Notes Section 3.3.1, 3.5.3

16.

3/4

Circulation Decomposition, Flow Decomposition, Disjoint Dipaths

Course Notes Section 3.6.1, 3.6.2

17.

3/9

Menger’s Theorem, Flows with Lower Bounds

Course Notes Section 3.6.2, 3.4

18.

3/11

Minimum Cost Flows

Course Notes Section 4.1, 4.2

19.

3/16

Sufficient conditions for feasible flows, Incrementing cycles

Course Notes Section 4.2, 4.3

20.

3/18

Incrementing Cycle Algorithm, Optimality Conditions

Course Notes Section 4.3, 4.4.3, 4.4.1

21.

3/23

Optimality Conditions, Tree Flows

Course Notes Section 4.4, 4.5

22.

3/25

Network Simplex Method

Course Notes Section 4.5

23.

3/30

Network Simplex Wrap-up & Example

Course Notes Section 4.5

24.

4/1

Class cancelled

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