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5d11121c14
Improvements to A* via using bitflags to find directions and caching already checked directions so we don't recheck them.
77 lines
1.5 KiB
Plaintext
77 lines
1.5 KiB
Plaintext
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//////////////////////
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//datum/Heap object
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//////////////////////
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/datum/Heap
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var/list/L
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var/cmp
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/datum/Heap/New(compare)
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L = new()
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cmp = compare
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/datum/Heap/proc/IsEmpty()
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return !L.len
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//Insert and place at its position a new node in the heap
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/datum/Heap/proc/Insert(atom/A)
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L.Add(A)
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Swim(L.len)
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//removes and returns the first element of the heap
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//(i.e the max or the min dependant on the comparison function)
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/datum/Heap/proc/Pop()
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if(!L.len)
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return 0
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. = L[1]
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L[1] = L[L.len]
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L.Cut(L.len)
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if(L.len)
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Sink(1)
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//Get a node up to its right position in the heap
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/datum/Heap/proc/Swim(var/index)
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var/parent = round(index * 0.5)
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while(parent > 0 && (call(cmp)(L[index],L[parent]) > 0))
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L.Swap(index,parent)
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index = parent
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parent = round(index * 0.5)
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//Get a node down to its right position in the heap
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/datum/Heap/proc/Sink(var/index)
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var/g_child = GetGreaterChild(index)
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while(g_child > 0 && (call(cmp)(L[index],L[g_child]) < 0))
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L.Swap(index,g_child)
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index = g_child
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g_child = GetGreaterChild(index)
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//Returns the greater (relative to the comparison proc) of a node children
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//or 0 if there's no child
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/datum/Heap/proc/GetGreaterChild(var/index)
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if(index * 2 > L.len)
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return 0
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if(index * 2 + 1 > L.len)
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return index * 2
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if(call(cmp)(L[index * 2],L[index * 2 + 1]) < 0)
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return index * 2 + 1
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else
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return index * 2
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//Replaces a given node so it verify the heap condition
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/datum/Heap/proc/ReSort(atom/A)
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var/index = L.Find(A)
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Swim(index)
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Sink(index)
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/datum/Heap/proc/List()
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. = L.Copy()
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