二分查询

public static int binarySearch(int[] array, int value){
  int low = 0;
  int high = array.length - 1;
  int middle;
  while(low <= high){
   middle = (low + high) / 2;
   if(array[middle] == value){
    return middle;
   }
   if(value < array[middle]){
    high = middle - 1;
   }
   if(value > array[middle]){
    low = middle + 1;
   }
  }
  return -1;
 }