Java实现二分法查找数组

public class binarySearchTest
{
    public static void main(String[] args) 
    {
        int[] a = {1,5,9,36,49,89,102};
        int c = 49;
        int pos = binarySearch(a,c);
        System.out.println(pos);
    }

    private static int binarySearch(int[] a, int c)
    {
        if(a.length == 0) return -1;

        int start = 0;
        int end = a.length - 1;
        int middle = (start + end) / 2;
        while(start <= end)
        {
            if(a[middle] == c) return middle;
            if(a[middle] < c)
            {
                start = middle + 1;
            }
            else
            {
                end = middle - 1;
            }

            middle = (start + end) / 2;
        }

        return -1;
    }
}