export default class BinarySearch {
    /**
     * Returns the index of the specified key in the specified array.
     *
     * @param  a the array of integers, must be sorted in ascending order
     * @param  target the search target
     * @return index of key in array a if present; -1 otherwise
     */
    static indexOf(a: number[], target: number): number;
    /**
     * Returns the index of the specified key in the specified array.
     * This function is poorly named because it does not give the <em>rank</em>
     * if the array has duplicate keys or if the key is not in the array.
     *
     * @param  key the search key
     * @param  a the array of integers, must be sorted in ascending order
     * @return index of key in array `a` if present; `-1` otherwise
     */
    static rank(key: number, a: number[]): number;
}