正经题解

简单，结构体就搞定

#include <bits/stdc++.h>
using namespace std;
double peoplet[1000],peopleg[1000];
struct student{
	double BMI;
	int id;
}a[1000];
bool cmp(student x,student y){
	return x.BMI > y.BMI;
}
int main(){
	int n;
	cin >> n;
	for(int i = 1;i <= n;i++){
		cin >> peoplet[i];
	}
	for(int i = 1;i <= n;i++){
		cin >> peopleg[i];
	}
	for(int i = 1;i <= n;i++){
		a[i].BMI = peoplet[i] / (peopleg[i] * peopleg[i]);
		a[i].id = i;
	}
	sort(a+1,a+n+1,cmp);
	for(int i = 1;i <= n;i++)cout << a[i].id << ' ';
	return 0;
}