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Dijkstra’s Algorithm

Chen
November 17, 2022

Dijkstra’s Algorithm

Chen

November 17, 2022
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  1. Dijkstra’s Algorithm
    Do Dijkstra’s on this graph, starting from A.
    Best distance to A: 0
    All other nodes: 1 (so far, unreachable)
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  2. Dijkstra’s Algorithm
    A is done. Choose shortest total distance (B at distance 3)
    From B, find a better path to C (3+3=6)
    Path to A is worse (3+3, worse than 0)
    53 / 71

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  3. Dijkstra’s Algorithm
    B is done. Choose shortest total distance (F at distance 4)
    Better path to E (4+5=9)
    Worse paths to A (4+4 vs 0) and D (4+2=6 vs 5)
    54 / 71

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  4. Dijkstra’s Algorithm
    F is done. Choose shortest total distance (D at distance 5)
    Better path for E (5+3 = 8 vs 9)
    Worse paths for other nodes
    55 / 71

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  5. Dijkstra’s Algorithm
    D is done. Choose shortest total distance (C at distance 6)
    Better path to E (6+1 = 7 vs 8)
    Worse paths to B and D
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  6. Dijkstra’s Algorithm
    C is done. Choose shortest total distance (E at distance 7)
    Worse paths everywhere
    57 / 71

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  7. Dijkstra’s Algorithm
    All nodes are done.
    Note we could have recorded paths in table
    Also could stop early if we only wanted a single destination.
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