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Thread: flightpaths, finding lowest cost -- lowest amount of crossovers

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    Default flightpaths, finding lowest cost -- lowest amount of crossovers

    I have a college assignment.
    I already have it working with a depth first search on the data structure [it's not a tree since there are loops]
    Basically, the professor just wants the program to find A path and the price of said path.
    I have that basically worked out. But I want to bring it a step further and offer "Lowest total price" option
    and "lowest amount of crossover flights" and perhaps if I'm feeling up to it "lowest total price" although that would use
    the same algorithm for the lowest total price.
    Basically, I was thinking about using iterative deepening depth first search but I heard that's only usable on data trees.
    What algorithm would I need to implement.?
    Basically what I have now:

    City class
    --String of name
    --Hashmap of cities that it connects to, price per connection
    --getname()
    --getDestMap()
    --addDest()
    --depthFirstSearch(City start, goalfunction isGoal, stack<City> result)
    Goalfunction is an interface

    Main class
    --hashmap of cities and theyre name

    scanner
    to add to the tree
    CODE REMOVED Since it's not needed anymore
    Last edited by CjStaal; May 8th, 2012 at 12:47 AM. Reason: removed code in case anyone in my java class decides to look on this


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    Default Re: flightpaths, finding lowest cost -- lowest amount of crossovers

    Try looking at Dijkstra's Algorithm.

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    CjStaal (May 8th, 2012)

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    Default Re: flightpaths, finding lowest cost -- lowest amount of crossovers

    That's exactly what I need! Thanks so much!! My "Graph" would be the hashmap I have in the main class? I've encapsulated it to be its own class.
    Here's the entire code

    deleted code since it's no longer needed

    The algorithm would work with the finding lowest cost, finding lowest time
    and if I set all distances to "1" it will find lowest amount of hops, correct?
    Would there be a faster algorithm to find the latter of the 3 situations?

    City.java would be the vertex class, and FlightInfo.java's hashmap would be the graph?
    Last edited by CjStaal; May 8th, 2012 at 01:38 AM.

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    Default Re: flightpaths, finding lowest cost -- lowest amount of crossovers

    Sounds right to me. There are other path-finding algorithms you can investigate, but they're all more or less based off of Dijkstra's algorithm with some sort of heuristic, or guess strategy.

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    Default Re: flightpaths, finding lowest cost -- lowest amount of crossovers

    I've looked up examples online of the algorithm, and I've decided to rework the entire project, AGAIN lol. Well, It's going to be right this time.

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