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;
}
}
