二分查找法例子

时间：2011-02-24 来源：Fly龙

public class Test
{
   public static void main(String[] args)
   {
       int[] arr = new int[]{1,4,5,6,8,10,33,55,66};
       int result = search(arr,40);
       System.out.println(result);
   }

   private static int search(int[] arr, int target){

       int start = 0;
       int end = arr.length - 1;
       int middle = (end - start) / 2;

       do{
           System.out.println("middle:"+middle+"   arr[middle]:"+ arr[middle]);
           if(target == arr[middle]){
               return middle;
           }else{
               if(target > arr[middle]){
                   start = middle + 1;
                   middle = ((end - start) / 2) + start;
               }else{
                   end = middle - 1;
                   middle = (end - start) / 2;
               }

           }
       }while(middle != 0);
       return -1;
   }
}