折半查找法例題分析？

package com.aozhi.test;

public class BinarySearch {

/*

* 循環(huán)實(shí)現(xiàn)二分查找算法arr[] 已排好序的數(shù)組x

* return 返回索引下標(biāo)

*/

public static int binarySearch(int[] arr, int x) {

int low = 0;

int high = arr.length - 1;

while (low <= high) {//判斷非空

int middle = (low + high) / 2;//折半從中間開始

if (x == arr[middle]) {//是中間的直接返回

return middle;

} else if (x < arr[middle]) {//因?yàn)樗怯行虻臄?shù)組，可以根據(jù)中間值作比較

high = middle - 1;

} else {

low = middle + 1;

}

}

return -1;

}

public static void main(String[] args) {

int[] arr = { 6, 12, 33, 87, 90, 97, 108, 561 };

System.out.println("循環(huán)查找：" + (binarySearch(arr, 6)));

}

}