原题链接：

https://www.acwing.com/blog/content/30368/
感谢Pobz题目的分享！

代码：

#include<bits/stdc++.h>
using namespace std;

const int N=1e4+10;
int a[N];
int main()
{
    int n;
    cin>>n;
    for(int i=0;i<n;i++)
        cin>>a[i];
    int target; cin>>target;
    int low=0,high=n-1;
    int ans=0;  //统计二分次数
    while(low<high)
    {
        ans++;
        int mid=(low+high)/2;
        if(target == a[mid])
            break;
        if(target < a[mid])
            high=mid-1;
        else
            low=mid+1;
    }
    cout<<ans;
    return 0;
}