package com.datastack.search; /**  * 二分查找  */ public class BinarySearch {     public static void main(String[] args) {         int[] arr = new int[]{1,2,3,4,5,6,7,8,9};         System.out.println(binarySearch(arr, 9));     }     public static int binarySearch(int[] array,int key){         int low = 0;         int hight = array.length -1;         int middle = 0;         while(low<=hight){             middle=(low+hight)/2;             int value = array[middle];             if(value>key){                 hight = middle-1;             }else if(value<key){                 low = middle+1;             }else{                 return middle;             }         }         return -1;     } }