STL min priority queue?

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  1. #1
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    STL min priority queue?

    There is a priority_queue object in stl that gives you a max priority queue but I cant figure out how to get a min queue out of it. I defined my own compare object as im using objects for the elements but there doesnt seem to be anything I can return (from the compare object) to get a min queue. Its either a max queue or some meaningless order. Any ideas?
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  2. #2
    and the hat of wrongness Salem's Avatar
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    > but I cant figure out how to get a min queue out of it
    Read it from the other end?
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    well its implemented as a heap so reading from the other end wont be in any particular order
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    If you just have your compare return greater instead of less, won't that work? Note that that's different than not less (which is greater or equal).

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    Why don't you just make the priority inverse ie 1/priority val.

  6. #6
    S Sang-drax's Avatar
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    This works for me:
    Code:
    struct compare 
    {
      bool operator()(const int& l, const int& r) 
      {
          return l > r;
      }
    };
    
    
    int main()
    {
        priority_queue<int,vector<int>, compare > pq;
        pq.push(3);
        pq.push(5);
        pq.push(1);
        pq.push(8);
        while (!pq.empty())
        {
            cout << pq.top() << endl;
            pq.pop();
        }
        cin.get();
    }
    Quote Originally Posted by dnysveen
    Why don't you just make the priority inverse ie 1/priority val.
    That would be surrendering!
    Last edited by Sang-drax : Tomorrow at 02:21 AM. Reason: Time travelling

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    Quote Originally Posted by Sang-drax

    That would be surrendering!
    What do you mean it would be surrendering?

  8. #8
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    Thanks sang. I actually did try that within the context of my actual program and it didnt work lol. Must have been some weird bug. Thanks for your input guys.
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