//.4.二分法查找数字
#if 0
int Find(int a[],int low,int high,int key)  //查找函数
{
if(low>high)    
return -1;
int mid=(low+high)/2;
if(a[mid]==key)
return mid;
else if(key<a[mid])
return  Find(a,low,mid-1,key);
else
return Find(a,mid+1,high,key);
}


void main()
{
int a[]={1,19,27,34,41,78,92,101,300,520};
int key;
cout<<"input key:";
cin>>key;
int n=sizeof(a)/sizeof(int);
int low=0;
int high=n-1;
int index=Find(a,low,high,key);
cout<<"index="<<index<<endl;
}
#endif