C++14(g++5.4) 解法, 执行用时: 152ms, 内存消耗: 3264K, 提交时间: 2020-05-20 16:49:27

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod=1e9+7;
const ll N=1e5+5;
ll n,a[N],b[N];
ll power(ll a,ll b){return b?power(a*a%mod,b/2)*(b%2?a:1)%mod:1;}
ll inv(ll x){return power(x,mod-2);}
main(){
    cin>>n;
    for(int i=0;i<n;i++) cin>>a[i];
    for(int i=0;i<n;i++) cin>>b[i];
    ll ans=1;
    for(int i=0;i<n;i++)
        ans=ans*(a[i]-b[i])%mod*inv(a[i])%mod;
    cout<<(mod+1-ans)%mod;
}

C++ 解法, 执行用时: 443ms, 内存消耗: 2336K, 提交时间: 2021-08-06 21:56:08

#include<bits/stdc++.h>
using namespace std;
int a[100005],b[100005];
#define mood 1000000007
int main()
{
	int n;
	long long fz=1,fm=1;
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
		fm=fm*a[i]%mood;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&b[i]);
		fz=fz*(a[i]-b[i])%mood;	
	}
	int js=0;
	while(js<mood)
	{
		if((fz+(js-1)*fm)%mood==0)
		{
			break;
		}
		js++;
	}
	cout<<js<<endl;
}

Python3(3.5.2) 解法, 执行用时: 173ms, 内存消耗: 18640K, 提交时间: 2020-05-18 12:13:39

n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
mod=1000000007
up=1
for i in range(n): up*=(a[i]-b[i]);up%=mod
down=1
for i in a: down*=i;down%=mod
down=pow(down,mod-2,mod)
ans=1-up*down%mod
while ans<0:ans+=mod
print(ans)