8/4/2019 087-Dijkstra’s Algorithm

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1krishna Acharjee

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Dijkstra’sAlgorithm

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1

4

2

5

3

d4

d3

d2

d5

Here, d3 is the smallest of the 4

distances.

Then from 1 to 2 ,SHORTEST

PATH is d2.

  If there is an edge from 3 to 2,

then d2 is the shortest path or 

not?

8/4/2019 087-Dijkstra’s Algorithm

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1

4

2

5

3

d4

d3

d2

d5

Next loop:If 

(d3 + w32 < d2)

then

we have found a shorter pathfrom 1 to 2, that is d3+w32 not

d2.

else

d2 remains as shortestdistance from 1 to 2.

w32

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1

4

2

5

3

d4

d3

d2

d5

Each loop:

We find shortest path fromstart node to one of the

node.

Continue until we hit our 

target node.

w32

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0

1

2

6

4

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2

2

1

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6

6

15 117

5

415

PROBLEM

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vertex 0 1 2 3 4 5 6∞ ∞ ∞ ∞ ∞ ∞

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d=0

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d=15

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d=0

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d=4

d=15

d=8

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d=0

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d=5

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d=0

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STOP

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SHORTEST PATHS

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THANK YOU