export declare class DisjointSet<T = number> {
    private _parentMap;
    private _rankMap;
    /**
     * Adds a new node to the disjoint set.
     *
     * @param node The node to add.
     *
     * @timeComplexity `O(1)`
     *
     * @returns Returns false if the node is already in the disjoint set.
     */
    add(node: T): boolean;
    /**
     * Finds the root of the set containing the given node.
     *
     * @param node The node to find.
     *
     * @timeComplexity `O(α(n))` where `α(n)` is the inverse Ackermann function
     *
     * @returns The representative node of the set, or null if the node
     * is not found.
     */
    find(node: T): T | void;
    /**
     * Finds the root of the set containing the given node.
     * It adds the node to the set if it does not exist.
     *
     * @param node The node to find or add.
     *
     * @timeComplexity `O(α(n))` where `α(n)` is the inverse Ackermann function
     *
     * @returns The representative node of the set.
     */
    findOrAdd(node: T): T;
    /**
     * Unites the sets containing the 2 given nodes.
     *
     * @param nodeA The first node.
     * @param nodeB The second node.
     *
     * @timeComplexity `O(α(n))` where `α(n)` is the inverse Ackermann function
     * of `n`.
     *
     * @returns Returns false if the 2 nodes are already in the same set.
     */
    union(nodeA: T, nodeB: T): boolean;
    /**
     * Clears the disjoint set.
     *
     * @timeComplexity `O(1)`
     */
    clear(): void;
    /**
     * Returns the number of elements in the disjoint set.
     *
     * @timeComplexity `O(1)`
     */
    size(): number;
}