Priority queue: Difference between revisions

=={{header|Picat}}==

Picat has built-in support for min and max heaps.

<lang Picat>main =>

Tasks = [[3,"Clear drains"],

[4,"Feed cat"],

[5,"Make tea"],

[1,"Solve RC tasks"],

[2,"Tax return"]],

Heap = new_min_heap([]),

foreach(Task in Tasks)

Heap.heap_push(Task),

println(top=Heap.heap_top())

end,

nl,

println(Heap),

println(size=Heap.heap_size),

nl,

println("Pop the elements from the queue:"),

println([Heap.heap_pop() : _ in 1..Heap.heap_size]).</lang>

{{out}}

<pre>top = [3,Clear drains]

top = [3,Clear drains]

top = [3,Clear drains]

top = [1,Solve RC tasks]

top = [1,Solve RC tasks]

_$heap(5,{[1,Solve RC tasks],[2,Tax return],[5,Make tea],[4,Feed cat],[3,Clear drains],_33c8},min)

size = 5

Pop the elements from the queue:

[[1,Solve RC tasks],[2,Tax return],[3,Clear drains],[4,Feed cat],[5,Make tea]]</pre>

The heaps creation functions can take the task list as argument:

<lang Picat> Tasks = [[3,"Clear drains"],

[4,"Feed cat"],

[5,"Make tea"],

[1,"Solve RC tasks"],

[2,"Tax return"]],

Heap = new_min_heap(Tasks),

println([Heap.heap_pop() : _ in 1..Heap.heap_size]).</lang>