Submission #985075

#	Time	Username	Problem	Language	Result	Execution time	Memory
985075		alexdd	Fancy Fence (CEOI20_fancyfence)	C++17	100 / 100	70 ms	5588 KiB

fancyfence

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int MOD = 1e9+7;
int n;
int h[100005];
int w[100005];
int nrp(int x)
{
    return (x*(x+1)/2LL)%MOD;
}
signed main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>h[i];
    }
    deque<pair<int,int>> dq;///{h, cnt}
    int sumdq=0,rez=0;
    for(int i=1;i<=n;i++)
    {
        cin>>w[i];
        int cnt = w[i];
        while(!dq.empty() && h[i] <= dq.back().first)
        {
            cnt += dq.back().second;
            cnt %= MOD;
            sumdq = (sumdq + MOD - nrp(dq.back().first) * dq.back().second)%MOD;
            dq.pop_back();
        }
        dq.push_back({h[i],cnt});
        rez += (sumdq*w[i])%MOD + nrp(h[i]) * (((cnt - w[i] + MOD)*w[i] + nrp(w[i]))%MOD);
        rez %= MOD;
        sumdq += (nrp(h[i]) * cnt)%MOD;
        sumdq %= MOD;
    }
    cout<<rez;
    return 0;
}

• 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