二分查找的算法

package test;

/**
 * @author 张牛俊
 * date :2010-5-11
 */
public class MySecondMidTest {

 public static void main(String[] args) {
  int [] data = {1,3,5,7,8,9,11,13};
  int position = binarySearch(data, 9);
  if(position == -1){
   System.out.println("没有找到相应的值");
  }else{
   System.out.println("找到了  位置为:"+position);
  }
 }
 
 public static int binarySearch(int data[],int value){
  int startIndex = 0;
  int endIndex = data.length-1;
  int midIndex = (int) Math.floor((endIndex-startIndex)/2);
  while(data[midIndex]!=value && startIndex   //调整查询的范围
   System.out.println("当前执行的比较为 数组的值:"+data[midIndex]+" value值为:"+value);
   if(value < data[midIndex]){
    endIndex = midIndex - 1;
   }else if(value>data[midIndex]){
    startIndex = midIndex+1;
   }
   //重新调整中间的位置
   midIndex = (int) Math.floor((endIndex+startIndex)/2);
  }
  return (data[midIndex]!=value) ? -1 :midIndex;
 }
}