Submission #745947

#	Time	Username	Problem	Language	Result	Execution time	Memory
745947		vjudge1	Fancy Fence (CEOI20_fancyfence)	C++17	13 / 100	52 ms	1404 KiB

fancyfence

// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

const long long MOD=1e9+7;

int main() {
	long long n;
	cin>>n;
	vector<long long> h(n);
	long long wossz=0, ans=0;
	for(long long i=0; i<n; i++){
		cin>>h[i];
	}
	vector<long long> ket;
	long long a;
	cin>>a;
	if(h[0]==2) ket.push_back(a);
	wossz+=a;
	for(long long i=1; i<n; i++){
		cin>>a;
		if(h[i]==h[i-1] && h[i]==2){
			ket.back()=(ket.back()+a)%MOD;
		}
		else if(h[i]==2){
			ket.push_back(a);
		}
		wossz=(wossz+a)%MOD;
	}
	for(long long x : ket){
		ans=(ans+(x*(x+1)%MOD))%MOD;
	}
	ans=(ans+(wossz*(wossz+1)/2)%MOD)%MOD;
	cout<<ans<<"\n";
}

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