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Replace the stack used for sibling search with a heap
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,57 @@ | ||
| export class Heap { | ||
| constructor(array, comparator) { | ||
| this.heap = array; | ||
| this.compare = comparator; | ||
| this.heapify(); | ||
| } | ||
| push(value) { | ||
| this.heap.push(value); | ||
| let index = this.heap.length - 1; | ||
| while (index > 0) { | ||
| let parent = Math.trunc((index - 1) / 2); | ||
| if (this.compare(this.heap[parent], this.heap[index])) { | ||
| break; | ||
| } | ||
| let tmp = this.heap[parent]; | ||
| this.heap[parent] = this.heap[index]; | ||
| this.heap[index] = tmp; | ||
| index = parent; | ||
| } | ||
| } | ||
| pop() { | ||
| let value = this.heap[0]; | ||
| this.heap[0] = this.heap[this.heap.length - 1]; | ||
| this.heap.pop(); | ||
| this.downHeap(0); | ||
| return value; | ||
| } | ||
| downHeap(index) { | ||
| let size = this.length; | ||
| let largest = index; | ||
| let left = 2 * index + 1; | ||
| let right = 2 * index + 2; | ||
| if (left < size && this.compare(this.heap[left], this.heap[largest])) { | ||
| largest = left; | ||
| } | ||
| if (right < size && this.compare(this.heap[right], this.heap[largest])) { | ||
| largest = right; | ||
| } | ||
| if (largest != index) { | ||
| // swap | ||
| let tmp = this.heap[index]; | ||
| this.heap[index] = this.heap[largest]; | ||
| this.heap[largest] = tmp; | ||
| // recurse down | ||
| this.downHeap(largest); | ||
| } | ||
| } | ||
| heapify() { | ||
| // start from middle | ||
| for (let i = Math.trunc((this.length / 2) - 1); i >= 0; --i) { | ||
| this.downHeap(i); | ||
| } | ||
| } | ||
| get length() { | ||
| return this.heap.length; | ||
| } | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,91 @@ | ||
| export class Heap<T> | ||
| { | ||
| public heap: T[]; | ||
| private compare; | ||
|
|
||
| constructor(array: T[], comparator: (a: T, b: T) => boolean) | ||
| { | ||
| this.heap = array; | ||
| this.compare = comparator; | ||
|
|
||
| this.heapify(); | ||
| } | ||
|
|
||
| public push(value: T) | ||
| { | ||
| this.heap.push(value); | ||
|
|
||
| let index = this.heap.length - 1; | ||
| while (index > 0) | ||
| { | ||
| let parent = Math.trunc((index - 1) / 2); | ||
|
|
||
| if (this.compare(this.heap[parent], this.heap[index])) | ||
| { | ||
| break; | ||
| } | ||
|
|
||
| let tmp = this.heap[parent]; | ||
| this.heap[parent] = this.heap[index]; | ||
| this.heap[index] = tmp; | ||
|
|
||
| index = parent; | ||
| } | ||
| } | ||
|
|
||
| public pop(): T | undefined | ||
| { | ||
| let value = this.heap[0]; | ||
|
|
||
| this.heap[0] = this.heap[this.heap.length - 1]; | ||
| this.heap.pop(); | ||
|
|
||
| this.downHeap(0); | ||
|
|
||
| return value; | ||
| } | ||
|
|
||
| private downHeap(index: number) | ||
| { | ||
| let size = this.length; | ||
|
|
||
| let largest = index; | ||
| let left = 2 * index + 1; | ||
| let right = 2 * index + 2; | ||
|
|
||
| if (left < size && this.compare(this.heap[left], this.heap[largest])) | ||
| { | ||
| largest = left; | ||
| } | ||
|
|
||
| if (right < size && this.compare(this.heap[right], this.heap[largest])) | ||
| { | ||
| largest = right; | ||
| } | ||
|
|
||
| if (largest != index) | ||
| { | ||
| // swap | ||
| let tmp = this.heap[index]; | ||
| this.heap[index] = this.heap[largest]; | ||
| this.heap[largest] = tmp; | ||
|
|
||
| // recurse down | ||
| this.downHeap(largest); | ||
| } | ||
| } | ||
|
|
||
| heapify() | ||
| { | ||
| // start from middle | ||
| for (let i = Math.trunc((this.length / 2) - 1); i >= 0; --i) | ||
| { | ||
| this.downHeap(i); | ||
| } | ||
| } | ||
|
|
||
| get length() | ||
| { | ||
| return this.heap.length; | ||
| } | ||
| } |