/**
 * A priority queue implementation using a binary heap.
 * Higher priority values are dequeued first.
 *
 * ## Features
 * - **enqueue(value, priority)**: Add element with priority
 * - **enqueueBack(value)**: Add element to the back with lowest priority
 * - **dequeue()**: Remove and return highest priority element
 * - **peek()**: View highest priority element without removing
 * - **peekPriority()**: View highest priority value
 * - **size**: Get number of elements
 * - **isEmpty**: Check if queue is empty
 * - **clear()**: Remove all elements
 * - **toArray()**: Get all elements as array
 * - **toArrayWithPriorities()**: Get all elements with priorities
 *
 * ## Time Complexity
 * - enqueue: O(log n)
 * - enqueueBack: O(log n)
 * - dequeue: O(log n)
 * - peek: O(1)
 * - peekPriority: O(1)
 *
 * @example
 * ```typescript
 * const queue = new PriorityQueue<string>();
 * queue.enqueue("low", 1);
 * queue.enqueue("high", 3);
 * queue.enqueue("medium", 2);
 *
 * console.log(queue.dequeue()); // "high"
 * console.log(queue.dequeue()); // "medium"
 * console.log(queue.dequeue()); // "low"
 * ```
 *
 * @example
 * ```typescript
 * // Initialize with elements
 * const queue = new PriorityQueue([
 *   { value: "task1", priority: 1 },
 *   { value: "task2", priority: 3 },
 *   { value: "task3", priority: 2 }
 * ]);
 *
 * console.log(queue.peek()); // "task2"
 * console.log(queue.peekPriority()); // 3
 * ```
 *
 * @template T - The type of elements stored in the queue
 */
export declare class PriorityQueue<T> {
    private heap;
    private minPriority;
    /**
     * Creates a new PriorityQueue instance.
     * @param initialElements - Optional array of initial elements with priorities
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * // or
     * const queue = new PriorityQueue([
     *   { value: "item1", priority: 10 },
     *   { value: "item2", priority: 5 }
     * ]);
     * ```
     */
    constructor(initialElements?: {
        value: T;
        priority: number;
    }[]);
    /**
     * Returns the number of elements in the queue.
     * @returns The number of elements in the queue
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("item", 1);
     * console.log(queue.size); // 1
     * ```
     */
    get size(): number;
    /**
     * Checks if the queue is empty.
     * @returns True if the queue is empty, false otherwise
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * console.log(queue.isEmpty); // true
     * queue.enqueue("item", 1);
     * console.log(queue.isEmpty); // false
     * ```
     */
    get isEmpty(): boolean;
    /**
     * Adds an element to the queue with a specified priority.
     * Higher priority values are dequeued first.
     * @param value - The value to add
     * @param priority - The priority value (higher values have higher priority)
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * queue.enqueue("medium", 5);
     * console.log(queue.dequeue()); // "high"
     * ```
     */
    enqueue(value: T, priority: number): void;
    /**
     * Adds an element to the end of the queue with lowest priority.
     * This element will be dequeued last (FIFO for equal lowest priority).
     *
     * @param value - The value to add
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("high", 10);
     * queue.enqueue("medium", 5);
     * queue.enqueueBack("back1");
     * queue.enqueueBack("back2");
     * console.log(queue.dequeue()); // "high"
     * console.log(queue.dequeue()); // "medium"
     * console.log(queue.dequeue()); // "back1"
     * console.log(queue.dequeue()); // "back2"
     * ```
     */
    enqueueBack(value: T): void;
    /**
     * Removes and returns the element with the highest priority.
     * @returns The element with highest priority, or undefined if queue is empty
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * console.log(queue.dequeue()); // "high"
     * console.log(queue.dequeue()); // "low"
     * console.log(queue.dequeue()); // undefined
     * ```
     */
    dequeue(): T | undefined;
    /**
     * Returns the element with the highest priority without removing it.
     * @returns The element with highest priority, or undefined if queue is empty
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * console.log(queue.peek()); // "high"
     * console.log(queue.size); // 2 (element not removed)
     * ```
     */
    peek(): T | undefined;
    /**
     * Returns the priority of the element with the highest priority.
     * @returns The highest priority value, or undefined if queue is empty
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * console.log(queue.peekPriority()); // 10
     * ```
     */
    peekPriority(): number | undefined;
    /**
     * Removes all elements from the queue.
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("item1", 1);
     * queue.enqueue("item2", 2);
     * console.log(queue.size); // 2
     * queue.clear();
     * console.log(queue.size); // 0
     * console.log(queue.isEmpty); // true
     * ```
     */
    clear(): void;
    /**
     * Returns an array of all elements in the queue (without removing them).
     * The order is not guaranteed to be sorted by priority.
     * @returns Array of all elements in the queue
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * queue.enqueue("medium", 5);
     * console.log(queue.toArray()); // ["high", "medium", "low"] (order may vary)
     * ```
     */
    toArray(): T[];
    /**
     * Returns an array of all elements with their priorities.
     * The order is not guaranteed to be sorted by priority.
     * @returns Array of all elements with their priorities
     * @example
     * ```typescript
     * const queue = new PriorityQueue<string>();
     * queue.enqueue("low", 1);
     * queue.enqueue("high", 10);
     * console.log(queue.toArrayWithPriorities());
     * // [{ value: "high", priority: 10 }, { value: "low", priority: 1 }] (order may vary)
     * ```
     */
    toArrayWithPriorities(): {
        value: T;
        priority: number;
    }[];
    /**
     * Updates the minimum priority when adding elements.
     * @param priority - The priority being added
     */
    private updateMinPriorityOnAdd;
    /**
     * Updates the minimum priority from all elements (used in constructor).
     */
    private updateMinPriority;
    /**
     * Builds a max heap from the current heap array.
     */
    private buildHeap;
    /**
     * Moves an element up the heap to maintain heap property.
     * @param index - The index of the element to move up
     */
    private heapifyUp;
    /**
     * Moves an element down the heap to maintain heap property.
     * @param index - The index of the element to move down
     */
    private heapifyDown;
    /**
     * Swaps two elements in the heap.
     * @param i - First index
     * @param j - Second index
     */
    private swap;
}