제출 #851257

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
851257		Jawad_Akbar_JJ	Fancy Fence (CEOI20_fancyfence)	C++14	0 / 100	11 ms	8080 KiB

fancyfence

#include <bits/stdc++.h>

using namespace std;
#define int long long
const int N = 1e5 + 10;
int r[N][3];
int w[N];
int h[N];
int mod = 1e9 + 7;
signed main(){
	int n;
	cin>>n;
	for (int i=1;i<=n;i++)
		cin>>h[i];
	int ans = 0;
	for (int i=1;i<=n;i++){
		cin>>w[i];
		int a = (w[i]*(w[i]+1))/2;
		a = a % mod;
		ans += a;
		ans %= mod;
		if (h[i]==2)
			ans += 2*a;
		ans %= mod;
	}
	for (int i=n;i>=1;i--){
		for (int j=1;j<=h[i];j++){
			r[i][j] = r[i+1][j];
			ans += (r[i][j]*j)%mod;
			ans %= mod;
			r[i][j] = r[i+1][j] + w[i];
			r[i][j] %= mod;
			// cout<<"At "<<i<<" "<<j<<" added "<<r[i][j]*j<<endl;
		}
	}
	cout<<ans<<endl;
}

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• Subtask 3: 0 / 13
• Subtask 4: 0 / 15
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