import { BaseCollection } from './base-collection';
import { Comparator } from '../types';
export interface PriorityQueue<T> {
    push(element: T, priority: number): void;
    pop(): T | undefined;
    front(): T | undefined;
}
export declare class PriorityQueue<T> extends BaseCollection<T> implements PriorityQueue<T> {
    private heap;
    constructor(comparator?: Comparator<T>);
    /**
     * Checks if the queue is empty. Returns true if empty, false otherwise.
     */
    isEmpty(): boolean;
    /**
     * Returns the number of elements in the queue.
     */
    size(): number;
    /**
     * Removes all elements from the queue.
     */
    clear(): void;
    /**
     * Checks if two priority queues are equal.
     */
    equals(other: PriorityQueue<T>): boolean;
}