简单算法--二分搜索

//二分搜索
 public int biSearch(int key,int[] intArray){
  
  int low = 0;
  int high = intArray.length-1;
  if(intArray[high] < key || intArray[low] > key) 
  { 
     System.out.println("This number is not in the range"); 
     return -1; 
  } 

  int middle = (low + high)/2 ;
  while(high>=low){
   if(intArray[middle] == key){
    System.out.println("find it");
    return middle;
   }else if(intArray[middle] < key){
    low = middle +1;
   }else{
    high = middle -1;
   }
   middle = (low + high)/2 ;
  }
  return -1;
 }