int find(int *arr,int low, int hight,int key)
{
    int mid=(hight+low)/2 ;
    if(arr[mid]==key) return mid;
    if(arr[mid]>key) return find(arr,low,mid-1,key);
    if(arr[mid]<key) return find(arr,mid+1,hight,key);
    else if (arr[mid]!=key) return -1;
}
int main()
{
  int  arr[]={1,2,3,4,5,6,7,9,16},key=9;
  int low=0,hight=8;
  printf("数组位置：%d", find(arr, low,  hight, key));
  getchar();
  return 0;
}