29 lines
906 B
Erlang
29 lines
906 B
Erlang
-module( priority_queue ).
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-export( [create/0, insert/3, peek/1, task/0, top/1] ).
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create() -> gb_trees:empty().
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insert( Element, Priority, Queue ) -> gb_trees:enter( Priority, Element, Queue ).
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peek( Queue ) ->
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{_Priority, Element, _New_queue} = gb_trees:take_smallest( Queue ),
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Element.
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task() ->
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Items = [{3, "Clear drains"}, {4, "Feed cat"}, {5, "Make tea"}, {1, "Solve RC tasks"}, {2, "Tax return"}],
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Queue = lists:foldl( fun({Priority, Element}, Acc) -> insert( Element, Priority, Acc ) end, create(), Items ),
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io:fwrite( "peek priority: ~p~n", [peek( Queue )] ),
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lists:foldl( fun(_N, Q) -> write_top( Q ) end, Queue, lists:seq(1, erlang:length(Items)) ).
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top( Queue ) ->
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{_Priority, Element, New_queue} = gb_trees:take_smallest( Queue ),
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{Element, New_queue}.
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write_top( Q ) ->
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{Element, New_queue} = top( Q ),
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io:fwrite( "top priority: ~p~n", [Element] ),
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New_queue.
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