/*
 * @project        practice_j2se
 * @file_name    BinarySearch.java
 */

package com.j2se.exec.way;

/**
 * @author        jhb
 * @version        1.0
 * @create_on    Oct 20, 2007 6:46:10 PM
 */
public class BinarySearch {

    public static void main(String[] args) {

        int[] array = new int[10];
        for (int i = 0; i < 10; i++)
            array[i] = (i + 1) * 10;

        int aimEle = 100;
        int position = new BinarySearch().search(array, aimEle, 0, 9);
        if (position == -1)
            System.out.println("找不到目标元素!");
        else
            System.out.println("目标" + aimEle + "的下标为:" + position);
    }

    public int search(int[] gather, int aim, int left, int right) {

        int mid = (left + right) / 2;

        if (aim == gather[mid])
            return mid;
        if (left == right)
            return -1;
        if (aim < gather[mid])
            right = mid - 1;
        if (aim > gather[mid])
            left = mid + 1;

        return search(gather, aim, left, right);
    }

}