@figliolia/data-structures/dist/mjs/Heap.js

Efficient data structures for every day programming

/**
 * Heap
 *
 * The base construct of the MinHeap and MaxHeap utilities
 */
export class Heap {
    storage = [];
    valueExtractor;
    constructor(valueExtractor) {
        this.valueExtractor = valueExtractor;
    }
    /**
     * Push
     *
     * Adds an element to the heap and positions it correctly
     */
    push(value) {
        this.storage.push(value);
        let curr = this.length - 1;
        while (curr > 0) {
            const parent = (curr - 1) >>> 1;
            if (this.comparer(curr, parent)) {
                break;
            }
            this.swap(curr, parent);
            curr = parent;
        }
    }
    /**
     * Pop
     *
     * Removes the last element in the heap
     */
    pop() {
        const N = this.length - 1;
        this.swap(0, N);
        const value = this.storage.pop();
        let curr = 0;
        let left = 0;
        while ((left = 2 * curr + 1) < this.length) {
            const minChildIndex = this.nextChild(left, left + 1);
            if (this.comparer(minChildIndex, curr)) {
                break;
            }
            this.swap(minChildIndex, curr);
            curr = minChildIndex;
        }
        return value;
    }
    get length() {
        return this.storage.length;
    }
    swap(index1, index2) {
        [this.storage[index1], this.storage[index2]] = [
            this.storage[index2],
            this.storage[index1],
        ];
    }
    extract(value) {
        if (typeof value === "number") {
            return value;
        }
        return this.valueExtractor(value);
    }
}