graphs – searching for relationships comp 200 & comp 130 john greiner & stephen wong
TRANSCRIPT
Graphs – Searching for Relationships
COMP 200 & COMP 130
John Greiner & Stephen Wong
Graphs – A Reminder
Vertices/nodes + edges connecting vertices
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3
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5
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Directed
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5
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Undirected
Social graph
How are you connected to
someone else?
Math co-authors, centered on Paul Erdös.
Can Introducing Hepocyte Growth Factor Lead to Apoptosis?
How are Two Species Related?
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Discovering Your Own Relations
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How to Solve a Maze?
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Solving a Maze: Right-Hand Rule
Good when you don’t know the maze layout.
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How to Get to Work?
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Focus on Three Algorithms
• Depth-first Search
• Breadth-first Search
• Dijkstra’s Shortest Path
First, just quick introductions to each.
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Depth- vs. Breadth-First Search
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1 2c
2b
2a
3c
4b
3b
3a
4a
DFS BFS
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Dijkstra’s Shortest Path
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0
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Dijkstra’s Shortest Path
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0
7?
3?
4?
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Dijkstra’s Shortest Path
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0
7?
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4?
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Dijkstra’s Shortest Path
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0
5?
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4?
8?
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Dijkstra’s Shortest Path
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7
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0
5?
3
4
8?
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Dijkstra’s Shortest Path
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5
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1
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0
5?
3
4
8?
6?
12?
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Dijkstra’s Shortest Path
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5
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2
7
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8
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0
5
3
4
8?
6?
12?
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Dijkstra’s Shortest Path
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5
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7
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8
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3
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0
5
3
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8?
6
12?
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Dijkstra’s Shortest Path
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5
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7
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3
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0
5
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8
6
12?
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Dijkstra’s Shortest Path
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7
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0
5
3
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8
6
9?
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Dijkstra’s Shortest Path
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2
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1
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0
5
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9
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Dijkstra’s Shortest Path
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5
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0
5
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8
6
913?
12?
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Dijkstra’s Shortest Path
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5
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2
7
1
8
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0
5
3
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8
6
913?
12
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Dijkstra’s Shortest Path
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5
3
2
7
1
8
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3
4
0
5
3
4
8
6
913
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