求条入门E题（80分）

#include<bits/stdc++.h>
//因为爱，所以坚持
using namespace std;
#define I return
#define love 0
#define coding
#define int long long

int n,x[100050],p[100050],q;
double ans1,ans2;

signed main(){
//	freopen("data.in","r",stdin);
//	freopen("task.out","w",stdout);
	cin>>n;
	for(int i = 1;i <= n;++i) cin>>x[i];
	for(int i = 1;i <= n;++i) cin>>p[i],q+=p[i];
	for(int i = 1;i <= n;++i) ans1+=x[i]*p[i];
	ans1 = (1.0*ans1/q);
	for(int i = 1;i <= n;++i){
		double k = 1.0*x[i]-ans1;
		ans2+=1.0*k*k;
	}
	ans2 = (1.0*ans2/q);
	printf("%.7lf\n%.7lf",ans1,ans2);
	I love coding;
}