/**
 * Lighter version of
 * Heap.ts from https://github.com/ignlg/heap-js/blob/master/src/Heap.ts
 * heap-js by @ignlg
 */
export type Comparator<T> = (a: T, b: T) => number;
export type IsEqual<T> = (e: T, o: T) => boolean;
export declare const toInt: (n: number) => number;
/**
 * Heap
 * @type {Class}
 */
export declare class Heap<T> {
    compare: Comparator<T>;
    heapArray: Array<T>;
    _limit: number;
    /**
     * Heap instance constructor.
     * @param  {Function} compare Optional comparison function, defaults to Heap.minComparator<number>
     */
    constructor(compare: Comparator<T>);
    /**
     * Gets children indices for given index.
     * @param  {Number} idx     Parent index
     * @return {Array(Number)}  Array of children indices
     */
    static getChildrenIndexOf(idx: number): Array<number>;
    /**
     * Gets parent index for given index.
     * @param  {Number} idx  Children index
     * @return {Number | undefined}      Parent index, -1 if idx is 0
     */
    static getParentIndexOf(idx: number): number;
    /**
     * Adds an element to the heap. Aliases: `offer`.
     * Same as: push(element)
     * @param {any} element Element to be added
     * @return {Boolean} true
     */
    push(element: T): boolean;
    /**
     * Length of the heap.
     * @return {Number}
     */
    length(): number;
    /**
     * Top node. Aliases: `element`.
     * Same as: `top(1)[0]`
     * @return {any} Top node
     */
    peek(): T | undefined;
    /**
     * Extract the top node (root). Aliases: `poll`.
     * @return {any} Extracted top node, undefined if empty
     */
    pop(): T | undefined;
    /**
     * Pop the current peek value, and add the new item.
     * @param  {any} element  Element to replace peek
     * @return {any}         Old peek
     */
    replace(element: T): T;
    /**
     * Size of the heap
     * @return {Number}
     */
    size(): number;
    /**
     * Move a node to a new index, switching places
     * @param  {Number} j First node index
     * @param  {Number} k Another node index
     */
    _moveNode(j: number, k: number): void;
    /**
     * Move a node down the tree (to the leaves) to find a place where the heap is sorted.
     * @param  {Number} i Index of the node
     */
    _sortNodeDown(i: number): void;
    /**
     * Move a node up the tree (to the root) to find a place where the heap is sorted.
     * @param  {Number} i Index of the node
     */
    _sortNodeUp(i: number): void;
}