Class MinHeap

heaps/min-heap-construction.js:1–64

class MinHeap {
    constructor(array) {
        this.heap = this.buildHeap(array);
    }
    
    buildHeap(array) {
        const firstParentIdx = Math.floor((array.length - 2) / 2);
        for(let currentIdx = firstParentIdx; currentIdx >= 0; currentIdx--) {
            this.siftDown(currentIdx, array.length - 1, array);
        }
        return array;
    }
    
    siftDown(currentIdx, endIdx, heap) {
        let childOneIdx = currentIdx * 2 + 1;
        while(childOneIdx <= endIdx) {
            const childTwoIdx = currentIdx * 2 + 2 <= endIdx ? currentIdx * 2 + 2 : -1;
            let idxToSwap;
            if(childTwoIdx !== -1 && heap[childTwoIdx] < heap[childOneIdx]) {
                idxToSwap = childTwoIdx;
            } else {
                idxToSwap = childOneIdx;
            }
            if(heap[idxToSwap] < heap[currentIdx]) {
                this.swap(currentIdx, idxToSwap, heap);
                currentIdx = idxToSwap;
                childOneIdx = currentIdx * 2 + 1;
            } else {
                return;
            }
        }
    }
    
    siftUp(currentIdx, heap) {
        let parentIdx = Math.floo((currentIdx - 1) / 2);
        while(currentIdx > 0 && heap[currentIdx] < heap[parentIdx]) {
            this.swap(currentIdx, parentIdx, heap);
            currentIdx = parentIdx;
            parentIdx = Math.floor((currentIdx - 1) / 2);
        }
    }
    
    peek() {
        return this.heap[0];
    }
    
    remove() {
        this.swap(0, this.heap.length - 1, this.heap);
        const valueToRemove = this.heap.pop();
        this.siftDown(0, this.heap.length - 1, this.heap);
        return valueToRemove;
    }
    
    insert(value) {
        this.heap.push(value);
        this.siftUp(this.heap.length - 1, this.heap);
    }
    
    swap(i, j, heap) {
        const temp = heap[j];