【微信聊天】5 张图帮你看懂二分查找

public static int binarySearch (int target,int[] ary) {
   int low = 0;
   int high = ary.length - 1;
   while (low <= high) {
       int middle = (low + high) >> 1;
       if (ary[middle] > target) {
           high = middle - 1;
       } else if (ary[middle] < target) {
           low = middle + 1;
       } else {
           return middle;
       }
   }
   return -1;
}