/**
 * Min-heap implementation for efficient priority queue operations in A* pathfinding.
 * Provides O(log n) insert and extract-min operations.
 */
export declare class MinHeap<T> {
    private keyFn;
    private heap;
    private itemMap;
    constructor(keyFn: (item: T) => string);
    /**
     * Insert an item with a given priority.
     * Time complexity: O(log n)
     */
    insert(item: T, priority: number): void;
    /**
     * Extract and return the item with minimum priority.
     * Time complexity: O(log n)
     */
    extractMin(): T | null;
    /**
     * Decrease the priority of an existing item.
     * Time complexity: O(log n)
     */
    decreaseKey(item: T, newPriority: number): void;
    /**
     * Check if the heap is empty.
     */
    isEmpty(): boolean;
    /**
     * Get the current size of the heap.
     */
    size(): number;
    /**
     * Bubble up an item to maintain heap property.
     */
    private bubbleUp;
    /**
     * Bubble down an item to maintain heap property.
     */
    private bubbleDown;
    /**
     * Swap two elements in the heap and update the item map.
     */
    private swap;
}
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