Java快速写一个二分法查找

Java快速写一个二分法查找

public class TestDemo {
    @org.junit.Test
    public void test2() {
        int[] a = new int[]{1, 2, 8, 1, 3};
        TestDemo testDemo = new TestDemo();
        int search = testDemo.binarySearch(a, 8);
        System.out.println(search);

    }

    public static int binarySearch(int[] array, int value) {
        int low = 0;
        int high = array.length - 1;
        while (low <= high) {
            int middle = (low + high) >> 1;
            if (value == array[middle]) {
                return middle;
            }
            if (value > array[middle]) {
                low = middle + 1;
            }
            if (value < array[middle]) {
                high = middle - 1;
            }

        }
        return -1;
    }

}

=================
快速查找是这样

    public static int search(int[] a, int key) {
        for (int i = 0, length = a.length; i < length; i++) {
            if (a[i] == key) {
                return i;
            }
        }
        return -1;
    }