# Can someone please explain Dijkstra's algorithm to me?

#1
The textbook examples aren't making sense to me, what's a working value and how do you know what numbers they are?
What does "order of labelling" mean?
0
1 year ago
#2
working values are a list of the possible numbers that could be the final value, the smallest of the working values becomes the final value. for every iteration you have to find a working value which is the number it would be to get from the start point to there, you do this for every possible vertex it could come from and then the smallest one is the final value.

order of labelling is the route you take, so if i go A to B to C to D, then C is 3 and D is 4.
send a picture of the question
1
#3
(Original post by Gent2324)
working values are a list of the possible numbers that could be the final value, the smallest of the working values becomes the final value. for every iteration you have to find a working value which is the number it would be to get from the start point to there, you do this for every possible vertex it could come from and then the smallest one is the final value.

order of labelling is the route you take, so if i go A to B to C to D, then C is 3 and D is 4.
send a picture of the question
How do I send photos?
It's not a question it's just how to do it.
https://www.pearsonactivelearn.com/a...Jvb2t8NjF8MA==
0
1 year ago
#4
(Original post by flumefan1)
How do I send photos?
It's not a question it's just how to do it.
https://www.pearsonactivelearn.com/a...Jvb2t8NjF8MA==
0
#5
(Original post by flumefan1)
How do I send photos?
It's not a question it's just how to do it.
https://www.pearsonactivelearn.com/a...Jvb2t8NjF8MA==
(Original post by Gent2324)
Haven't got a clue how to do that sorry!
So how do I know what the working values are going to be? Are they just the lengths of the arcs?
0
1 year ago
#6
(Original post by flumefan1)
Haven't got a clue how to do that sorry!
So how do I know what the working values are going to be? Are they just the lengths of the arcs?
no, its the length of the route to get there.
For example, If i want to go from A to D, i can go A to B to D, or i can go A to C to D.
My working values will be A to B to D which is the total length of going through those vertices, and also A to C to D which could be a different number.
Whatever those values are, you write them in the lower-rectangle of the box on D. if they are the only possible routes to get to D, you select the lowest number out of those 2 working values, and you write it in the 3rd box on the top. The second box is the order of labelling which is just the 2nd 3rd 4th etc vertex you have a final value for. in this example we dont know what the order of labelling is.
0
1 year ago
#7
(Original post by flumefan1)
The textbook examples aren't making sense to me, what's a working value and how do you know what numbers they are?
What does "order of labelling" mean?
Try googling step by step example - it's hard to explain without diagrams.
0
#8
Thank you both
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