算法--二分法查找

新浪的笔试题，二分法查找算法。

package com.gp.common.util;

import java.util.List;
/**
 * 二分法查询算法
 * @author Administrator
 *
 */
public class UtilMethod

{

	public static int binary(int[] array, int value)

	{

		int low = 0;

		int high = array.length - 1;

		while (low <= high)

		{

			int middle = (low + high) / 2;

			if (value == array[middle])

			{

				return middle;

			}

			if (value > array[middle])

			{

				low = middle + 1;

			}

			if (value < array[middle])

			{

				high = middle - 1;

			}

		}

		return -1;

	}

	public static void main(String[] args)

	{

		int[] a = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

		int value = binary(a, 9);

		System.out.println(value);

	}

}