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# D1 kruskal / Prims algorithm watch

1. hi, I am a bit stuck on part b as I don'tnt get why kruskals algorithm would be the answer. Here is my answer Attachment 611600611602 the answer says the by using kruskal , you can set AB and FI As the starting point but there are arcs with a smaller weightht than AB so I don't get how the arcs can be arranged in an ascending order....

Thanks
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2. (Original post by coconut64)
hi, I am a bit stuck on part b as I don'tnt get why kruskals algorithm would be the answer. Here is my answer; the answer says the by using kruskal , you can set AB and FI As the starting point but there are arcs with a smaller weightht than AB so I don't get how the arcs can be arranged in an ascending order....

Thanks
Prim's algorithm builds up a network by joining nodes progressively, you can't use prim's algorithm as the arcs that are connected at the start aren't connected by a common node. You can however use kruskal's by just setting AB and FI as mandatory to add to the network and then following the algorithm as usual.
3. (Original post by NotNotBatman)
Prim's algorithm builds up a network by joining nodes progressively, you can't use prim's algorithm as the arcs that are connected at the start aren't connected by a common node. You can however use kruskal's by just setting AB and FI as mandatory to add to the network and then following the algorithm as usual.
Thanks. So you are suggesting that it is not guaranteed that AB and FI will be joined by a common node, but Kruskal definitely will? Just double checkING
tHANKS
4. (Original post by coconut64)
Thanks. So you are suggesting that it is not guaranteed that AB and FI will be joined by a common node, but Kruskal definitely will? Just double checkING
tHANKS
You can't start prim's algorithm if there are random arcs connected, as it is supposed to be built up form a single node. Whereas kruskals adds arcs from anywhere on a network, so you can use kruskals.
5. (Original post by NotNotBatman)
You can't start prim's algorithm if there are random arcs connected, as it is supposed to be built up form a single node. Whereas kruskals adds arcs from anywhere on a network, so you can use kruskals.
Thanks a lot for the help

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