109 lines
3.3 KiB
JavaScript
109 lines
3.3 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
class BinaryHeap {
|
|
constructor(options) {
|
|
options = options || {};
|
|
this._elements = options.elements || [];
|
|
this._score = options.score || this._score;
|
|
}
|
|
add() {
|
|
for (let i = 0; i < arguments.length; i++) {
|
|
const element = arguments[i];
|
|
this._elements.push(element);
|
|
this._bubble(this._elements.length - 1);
|
|
}
|
|
}
|
|
first() {
|
|
return this._elements[0];
|
|
}
|
|
removeFirst() {
|
|
const root = this._elements[0];
|
|
const last = this._elements.pop();
|
|
if (this._elements.length > 0) {
|
|
this._elements[0] = last;
|
|
this._sink(0);
|
|
}
|
|
return root;
|
|
}
|
|
clone() {
|
|
return new BinaryHeap({
|
|
elements: this.toArray(),
|
|
score: this._score
|
|
});
|
|
}
|
|
toSortedArray() {
|
|
const array = [];
|
|
const clone = this.clone();
|
|
while (true) {
|
|
const element = clone.removeFirst();
|
|
if (element === undefined)
|
|
break;
|
|
array.push(element);
|
|
}
|
|
return array;
|
|
}
|
|
toArray() {
|
|
return [].concat(this._elements);
|
|
}
|
|
size() {
|
|
return this._elements.length;
|
|
}
|
|
_bubble(bubbleIndex) {
|
|
const bubbleElement = this._elements[bubbleIndex];
|
|
const bubbleScore = this._score(bubbleElement);
|
|
while (bubbleIndex > 0) {
|
|
const parentIndex = this._parentIndex(bubbleIndex);
|
|
const parentElement = this._elements[parentIndex];
|
|
const parentScore = this._score(parentElement);
|
|
if (bubbleScore <= parentScore)
|
|
break;
|
|
this._elements[parentIndex] = bubbleElement;
|
|
this._elements[bubbleIndex] = parentElement;
|
|
bubbleIndex = parentIndex;
|
|
}
|
|
}
|
|
_sink(sinkIndex) {
|
|
const sinkElement = this._elements[sinkIndex];
|
|
const sinkScore = this._score(sinkElement);
|
|
const length = this._elements.length;
|
|
while (true) {
|
|
let swapIndex;
|
|
let swapScore;
|
|
let swapElement = null;
|
|
const childIndexes = this._childIndexes(sinkIndex);
|
|
for (let i = 0; i < childIndexes.length; i++) {
|
|
const childIndex = childIndexes[i];
|
|
if (childIndex >= length)
|
|
break;
|
|
const childElement = this._elements[childIndex];
|
|
const childScore = this._score(childElement);
|
|
if (childScore > sinkScore) {
|
|
if (swapScore === undefined || swapScore < childScore) {
|
|
swapIndex = childIndex;
|
|
swapScore = childScore;
|
|
swapElement = childElement;
|
|
}
|
|
}
|
|
}
|
|
if (swapIndex === undefined)
|
|
break;
|
|
this._elements[swapIndex] = sinkElement;
|
|
this._elements[sinkIndex] = swapElement;
|
|
sinkIndex = swapIndex;
|
|
}
|
|
}
|
|
_parentIndex(index) {
|
|
return Math.floor((index - 1) / 2);
|
|
}
|
|
_childIndexes(index) {
|
|
return [
|
|
2 * index + 1,
|
|
2 * index + 2
|
|
];
|
|
}
|
|
_score(element) {
|
|
return element.valueOf();
|
|
}
|
|
}
|
|
exports.default = BinaryHeap;
|