IterativeBinarySearch.java

package com.thealgorithms.searches;

import com.thealgorithms.devutils.searches.SearchAlgorithm;

/**
 * Binary search is one of the most popular algorithms This class represents
 * iterative version {@link BinarySearch} Iterative binary search is likely to
 * have lower constant factors because it doesn't involve the overhead of
 * manipulating the call stack. But in java the recursive version can be
 * optimized by the compiler to this version.
 *
 * <p>
 * Worst-case performance O(log n) Best-case performance O(1) Average
 * performance O(log n) Worst-case space complexity O(1)
 *
 * @author Gabriele La Greca : https://github.com/thegabriele97
 * @author Podshivalov Nikita (https://github.com/nikitap492)
 * @see SearchAlgorithm
 * @see BinarySearch
 */
public final class IterativeBinarySearch implements SearchAlgorithm {

    /**
     * This method implements an iterative version of binary search algorithm
     *
     * @param array a sorted array
     * @param key the key to search in array
     * @return the index of key in the array or -1 if not found
     */
    @Override
public <T extends Comparable<T>> int find(T[] array, T key) {
    if (array == null || array.length == 0) {
        return -1;
    }

    int l = 0;
    int r = array.length - 1;

    while (l <= r) {
        int mid = (l + r) >>> 1;
        int cmp = key.compareTo(array[mid]);

        if (cmp == 0) {
            return mid;
        } else if (cmp < 0) {
            r = mid - 1;
        } else {
            l = mid + 1;
        }
    }

    return -1;
}