算法--二分法查找

时间:2021-12-03 22:09:46

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);

}

}