java ¶þ·Ö·¨

public class Test4 {
 public int binarySearch(int[] items, int value){
  
     int startIndex  = 0;
     int stopIndex   = items.length - 1;
     int middle      = (int)Math.floor((stopIndex + startIndex)/2);
 
     while(items[middle] != value && startIndex < stopIndex){
 
         //adjust search area£¨µ÷Õû²éÕÒ·¶Î§£©
         if (value < items[middle]){
             stopIndex = middle - 1;
         } else if (value > items[middle]){
             startIndex = middle + 1;
         }
 
         //recalculate middle£¨ÖØмÆËãÖÐÏîË÷Òý£©
         middle = (int)Math.floor((stopIndex + startIndex)/2);
     }
 
     //make sure it's the right value£¨È·±£·µ»ØÕýÈ·µÄÖµ£©
     return (items[middle] != value) ? -1 : middle;
 }
 /**
  * @param args
  */
 public static void main(String[] args) {
  Test4 t = new Test4();
  int aa[]={1,3,5,7,9};
  System.out.println("!!!!!!!!!!!!!!!!!!!!!!!"+t.binarySearch(aa, 5));
 }
}