#include<iostream>
using namespace std;
int main(){
	int n,a[1005];
	cout<<"请输入数组长度：";
	cin>>n;
	int l,r=n-1,mid,t;
	cout<<"请输入需要查找的数：";
	cin>>t;
	cout<<"请输入数组：";
	for(int i=1;i<=n;i++)cin>>a[i];
	while(1){
		mid=(l+r)/2;
		if(a[mid]==t){
			cout<<"该数在数组的第"<<mid<<"位!";
			break;
		}
		if(t>a[mid])l=mid+1;
		else r=mid-1;
		if(l>r){
			cout<<"Not found!";
			break;
		}
	}
	return 0;
}