二分查找

package paixu;


public class erfenchazhao {


public static void main(String[] args) {
// TODO Auto-generated method stub


Integer a[]={1,2,3,4,6,8,9,10};

System.out.println(binarySearch(a,3));
}


public static int binarySearch(Integer[] a, int ycds) {


int low=0;
int high=a.length-1;

while(low<=high)
{
int mid=(low+high)/2;
if(ycds==a[mid])
return mid;
else if(ycds<a[mid])
{
high=mid-1;
}else if(ycds>a[mid])
{
low=mid+1 ;
}

}


return -1;
}


}