不记得当时教什么了，当时窝做这题出bug懒得重构，于是写了：

#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int n, a[133], lm, rm, li, ri;

int main() {
	scanf("%d", &n);
	lm = rm = -2147483648;
	for(int i = 1; i <= (1 << n); i ++)
		scanf("%d", &a[i]);
	for(int i = 1; i <= (1 << n) / 2; i ++)
		if(a[i] > lm)
			lm = a[i], li = i;
	for(int i = (1 << n) / 2 + 1; i <= (1 << n); i ++)
		if(a[i] > rm)
			rm = a[i], ri = i;
	printf("%d", lm < rm ? li : ri);
	return 0;
}

结果AC了