求助大佬！5个点WA了4个

代码：

#include <bits/stdc++.h>
using namespace std;
const int maxn=130;
int n,a[130];
int dfs(int x,int y){
    if(x==y){
        return x;
    }
    int x1=dfs(x,x+(y-x)/2);
    int y1=dfs(x+(y-x)/2+1,y);
    return  (x==1&&y==n)?((a[x1]<a[y1])?x1:y1):((a[x1]>a[y1])?x1:y1);
}

int main(){
    
    cin>>n;
    for(int i=1;i<=1<<n;i++){
        cin>>a[i];
    }
    //auto f=[](int x,int y){if(x==y) return x;int x1=f(x,x+(y-x)/2);int y1=f(x+(y-x)/2+1,y);return  (x==1&&y==n)?((a[x1]<a[y1])?x1:y1):((a[x1]>a[y1])?x1:y1);};
    cout<<dfs(1,n)<<endl;
    //return 0;
    return 0;
}