제출 #1277660

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1277660		PlayVoltz	Fancy Fence (CEOI20_fancyfence)	C++20	100 / 100	22 ms	3544 KiB

fancyfence

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
using namespace std;
 
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

const int MOD = 1000000007;

int inv(int num){
	int p=MOD, res=1, y=0;
	while (num>1){
		int q=num/p, t=p;
		p=num%p, num=t, t=y, y=res-q*y, res=t;
	}
	if (res<0)res+=MOD;
	return res;
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, ans=0, t=0;
	cin>>n;
	vector<pii> vect(n);
	for (int i=0; i<n; ++i)cin>>vect[i].fi;
	for (int i=0; i<n; ++i)cin>>vect[i].se;
	deque<pii> deq;
	for (int i=0; i<n; ++i){
		ans=(ans+((((((vect[i].fi*(vect[i].fi+1))%MOD)*vect[i].se)%MOD)*(vect[i].se+1))%MOD)*inv(4))%MOD;
		int w=0;
		while (deq.size()&&deq.back().fi>=vect[i].fi){
			w+=deq.back().se;
			t=(t-((((deq.back().se*deq.back().fi)%MOD)*(deq.back().fi+1))%MOD)*inv(2)+MOD)%MOD;
			deq.pop_back();
		}
		w%=MOD;
		t=(t+((((w*vect[i].fi)%MOD)*(vect[i].fi+1))%MOD)*inv(2))%MOD;
		deq.pb(mp(vect[i].fi, w));
		ans=(ans+vect[i].se*t)%MOD;
		w=vect[i].se;
		while (deq.size()&&deq.back().fi>=vect[i].fi){
			w+=deq.back().se;
			t=(t-((((deq.back().se*deq.back().fi)%MOD)*(deq.back().fi+1))%MOD)*inv(2)+MOD)%MOD;
			deq.pop_back();
		}
		w%=MOD;
		t=(t+((((w*vect[i].fi)%MOD)*(vect[i].fi+1))%MOD)*inv(2))%MOD;
		deq.pb(mp(vect[i].fi, w));
	}
	cout<<ans;
}

• Subtask 1: 0 / 0
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 18 / 18
• Subtask 7: 27 / 27