package com.gg.test;
public class BinarySearch{
public static void main(String[] args){
int[] a={1,2,3,4,5,6,7,8,9,10};
int i =7;
BinarySearch bs = new BinarySearch();
System.out.println("所处位置: "+bs.find(a,i));
}
public int find(int[] a,int searchKey){
int lowerBound =0; //最低限度
int upperBound =a.length-1; //最高限度,从0开始,数组长度a.length-1
int curIn;
while(true){ //死循环
curIn = (lowerBound+upperBound)/2; //二分查找
if(a[curIn]==searchKey){
return curIn;
}else if(lowerBound>upperBound){ //数组最短长度返回-1
return -1;
}else{
if(a[curIn]<searchKey){
lowerBound = curIn+1;
}else{
upperBound = curIn-1;
}
}
}
}
}