pq2

Priority queue w/ decrease key operation, good for Dijkstra's algorithm

npm install pq2
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node-pq

A Priority Queue for NodeJS in CoffeeScript. It offers three major operations: enq, deq, and change_key. You can use it to manage the nodes to visit in Dijkstra's algorithm. By default, the minimum object is at the top of the heap, though you can change the ordering with your own comparitor function.

Install

npm install pq2

Use

pq = new ProrityQueue {}
pq.enq { key : 'max', priority : 3 }     # returns 1, the new size of the PQ
pq.enq { key : 'blah', priority : 1 }    # returns 2, etc...
pq.peek()                                # returns { key : 'blah', priority : 1 }
pq.deq()                                 # returns { key : 'blah', priority : 1 }
pq.peek()                                # returns { key : 'max', priority : 3 }
pq.deq()                                 # returns { key : 'max', priority : 3 }
pq.enq { key : 'max', priority : 3 }     # returns 1, the new size of the PQ
pq.enq { key : 'blah', priority : 1 }    # returns 2, etc...
pq.change_key 'max', -3                  # returns null
pq.deq()                                 # returns { key : 'max', priority : -3 }

Contributors

Written by @maxtaco

The original template for this PQ is from @janogonzalez's priorityqueuejs, available at https://github.com/janogonzalez/priorityqueuejs

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