public class BiSearch { 
    public static void main(String[] args) { 
    new BiSearch().biFind(new int []{1,2,3,4,5,6,7},3); 
  } 
    public void biFind(int arr[],int y){ 
    int start=0; 
    int end=arr.length-1; 
    int mid=(start+end)/2; 
     
    while(start<=end){ 
      if(y==arr[mid]){ 
            System.out.println("查找成功，其下标为"+mid); 
         break; 
      } 
      if(y>arr[mid]){ 
           start=mid+1; 
           mid=(start+end)/2; 
         } 
      if(y<arr[mid]){ 
           end=mid-1; 
           mid=(start+end)/2; 
        } 
      if(start>end){ 
        System.out.println("查找失败"); 
 
      } 
    } 
  } 
}