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Chapter 13 Network Flows: Lec 16 13.1 Flows and Cuts in Networks 13.2 Solving the Maximum-Flow Problem 1 c 2010 by Jonathan L. Gross

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Page 1: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Chapter 13Network Flows: Lec 16

13.1 Flows and Cuts in Networks13.2 Solving the Maximum-Flow Problem

1 c 2010 by Jonathan L. Gross

Page 2: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

2 Chapter 13 Network Flows: Lec 16

13.1 FLOWS AND CUTS IN NETWORKS

c 2010 by Jonathan L. Gross

Page 3: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 3

Figure 13.1.1

c 2010 by Jonathan L. Gross

Page 4: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

4 Chapter 13 Network Flows: Lec 16

Feasible Flows

c 2010 by Jonathan L. Gross

Page 5: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 5

Fig 13.1.2

c 2010 by Jonathan L. Gross

Page 6: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

6 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 7: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 7

Cuts in - Networks

Fig 13.1.3

c 2010 by Jonathan L. Gross

Page 8: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

8 Chapter 13 Network Flows: Lec 16

Fig 13.1.4

c 2010 by Jonathan L. Gross

Page 9: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 9

Fig 13.1.5

c 2010 by Jonathan L. Gross

Page 10: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

10 Chapter 13 Network Flows: Lec 16

Relationship Between Flows and Cuts

c 2010 by Jonathan L. Gross

Page 11: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 11

Fig 13.1.6

c 2010 by Jonathan L. Gross

Page 12: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

12 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 13: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 13

Figure 13.1.7

c 2010 by Jonathan L. Gross

Page 14: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

14 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 15: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 15

Max-Flow Problem and Min-Cut Problem

c 2010 by Jonathan L. Gross

Page 16: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

16 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 17: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.1 Flows and Cuts in Networks 17

Fig 13.1.8

c 2010 by Jonathan L. Gross

Page 18: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

18 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 19: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 19

13.2 SOLVING FOR MAXIMUM-FLOW

Using Directed Paths to Augment Flow

c 2010 by Jonathan L. Gross

Page 20: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

20 Chapter 13 Network Flows: Lec 16

Figure 13.2.1

c 2010 by Jonathan L. Gross

Page 21: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 21

Figure 13.2.2

c 2010 by Jonathan L. Gross

Page 22: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

22 Chapter 13 Network Flows: Lec 16

-Augmenting Paths

Fig 13.2.3

c 2010 by Jonathan L. Gross

Page 23: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 23

c 2010 by Jonathan L. Gross

Page 24: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

24 Chapter 13 Network Flows: Lec 16

Figure 13.2.4

c 2010 by Jonathan L. Gross

Page 25: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 25

Figure 13.2.5

c 2010 by Jonathan L. Gross

Page 26: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

26 Chapter 13 Network Flows: Lec 16

c 2010 by Jonathan L. Gross

Page 27: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 27

Max-Flow Min-Cut Theorem

c 2010 by Jonathan L. Gross

Page 28: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

28 Chapter 13 Network Flows: Lec 16

Algo 13.2.1:

c 2010 by Jonathan L. Gross

Page 29: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 29

Finding an -Augmenting Path

c 2010 by Jonathan L. Gross

Page 30: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

30 Chapter 13 Network Flows: Lec 16

Figure 13.2.7

c 2010 by Jonathan L. Gross

Page 31: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 31

Algo 13.2.2:

c 2010 by Jonathan L. Gross

Page 32: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

32 Chapter 13 Network Flows: Lec 16

Algo 13.2.3:

c 2010 by Jonathan L. Gross

Page 33: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.2 Solving for Maximum-Flow 33

Figure 13.2.8

Figure 13.2.9

c 2010 by Jonathan L. Gross

Page 34: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

34 Chapter 13 Network Flows: Lec 16

Figure 13.2.10

Figure 13.2.11

c 2010 by Jonathan L. Gross

Page 35: Chapter 13cs4203/files/GT-Lec16.pdfChapter 13 Netw or k Flo ws: Lec 16 13.1 Flo ws and Cuts in Netw orks 13.2 Solving the Maxim um-Flo w P ro b lem 1 c 2010 b y Jonathan L. Gross

Section 13.5 Supplementary Exercises 35

Figure 13.2.12

13.5 SUPPLEMENTARY EXERCISES

c 2010 by Jonathan L. Gross