export declare class SkipListNode<T> {
    value: T | null;
    previous: SkipListNode<T> | null;
    next: SkipListNode<T> | null;
    up: SkipListNode<T> | null;
    down: SkipListNode<T> | null;
    constructor(value: T | null);
}
export declare class SkipList<T> {
    private compare;
    private head;
    private tail;
    private height;
    private _size;
    get size(): number;
    constructor(compare: (a: T, b: T) => number);
    elements(): IterableIterator<SkipListNode<T>>;
    dumpList(): Array<Array<T | null | undefined>>;
    delete(value: T): void;
    has(value: T): boolean;
    findNode(value: T): SkipListNode<T> | null;
    add(value: T): void;
    private findPreviousNode;
}