Submission #790899

#	Time	Username	Problem	Language	Result	Execution time	Memory
790899		12345678	Fancy Fence (CEOI20_fancyfence)	C++17	55 / 100	40 ms	8776 KiB

fancyfence

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const ll nx=1e5+5, mod=1e9+7;
ll n, ans, h, w, sm, H[nx], W[nx];
stack<pair<pair<ll, ll>, ll>> s;

ll cal(ll x)
{
    return (x*(x+1)/2)%mod;
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=0; i<n; i++) cin>>H[i];
    for (int i=0; i<n; i++) cin>>W[i];
    for (int i=0; i<n; i++)
    {
        ll h=H[i], w=W[i];
        ans=(ans+(cal(h)*cal(w))%mod)%mod;
        ll sw=0;
        while (!s.empty()&&s.top().first.first>h)
        {
            sw+=s.top().first.second;
            sm=((sm-s.top().second)%mod+mod)%mod;
            s.pop();
        }
        ll tmp=(cal(h)*sw)%mod;
        s.push({{h, sw}, tmp});
        sm=(sm+tmp)%mod;
        ans=(ans+sm*w)%mod;
        tmp=(cal(h)*w)%mod;
        s.push({{h, w}, tmp});
        sm=(sm+tmp)%mod;
    }
    cout<<ans;
}

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