#include<iostream>
using namespace std;
int search(int arr[],int key,int high,int low);
    int main()
	{
	    int n, searchkey,ch[1000];
	    while(1)
	    {
	    cin>>n;
	 	cout<<"请输入数组"<<endl;
	 	for(int i=0;i<n;i++)
		{
	      	cin>>ch[i];			
		}
	 	cout<<"请输入要查找的关键字"<<endl;
		 cin>>searchkey; 
		 int high=n-1;
		 int low=0;
		 。 
		  //searchresult=-1;            
     	int	 searchresult=search(ch,searchkey,high,low);
		 cout<<"要查询的索引为："<<searchresult<<endl;
		}
		 system("pause");
		}
		int search(int arr[],int key,int high,int low)
		{
			    int   mid=(low+high)/2;   
		        if(high<low)
				{
		          	return -1;	
			    }         
			    else if(arr[mid]==key)
                {
                    return mid;
                }
                else if(key<arr[mid])
                {
                    return search(arr,key,low,mid-1);
                }
                else if(key>arr[mid])
                {
                    return search(arr,key,mid+1,high);
                }
               //// cout<<mid<<endl;
        }

如果测试数据是3（1,4,5）然后关键字是2，程序没有运行结果，自动跳走