Submission #1155757

#	Time	Username	Problem	Language	Result	Execution time	Memory
1155757		ace5	Fancy Fence (CEOI20_fancyfence)	C++20	100 / 100	60 ms	6580 KiB

fancyfence

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const ll INF = 1e18;
const int mod = int(1e9)+7;

vector<pair<ll,pair<ll,ll>>> ev;
set<pair<ll,ll>> seg;
ll cans = 0;
ll res = 0;

ll get_ans(ll rh,ll lh)
{
    return (cans * ((rh * (rh+1) /2 - lh * (lh+1) /2)%mod))%mod;
}
ll get_cans(pair<ll,ll> cseg)
{
    __int128 len = cseg.second-cseg.first;
    return (len * (len+1) / 2) % mod;
}

void ins(pair<ll,ll> tseg)
{
   // cout << tseg.first << ' ' << tseg.second << "\n";
    auto it = seg.lower_bound(tseg);
    pair<ll,ll> ro = {INF,INF};
    if(it != seg.end())
        ro = (*it);
    pair<ll,ll> lo = {-INF,-INF};
    if(it != seg.begin())
    {
        lo = *(--it);
    }
    if(lo.second == tseg.first)
    {
        seg.erase(lo);
        cans = (cans-get_cans(lo)+mod)%mod;
        tseg.first = lo.first;
    }
    if(ro.first == tseg.second)
    {
        seg.erase(ro);
        cans = (cans-get_cans(ro)+mod)%mod;
        tseg.second = ro.second;
    }
    seg.insert(tseg);
    cans = (cans + get_cans(tseg))%mod;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    ll h[n],l[n],r[n];
    for(int i = 0;i < n;++i)
    {
        cin >> h[i];
    }
    for(int i = 0;i < n;++i)
    {
        cin >> r[i];
        r[i] += (i == 0 ? 0 : r[i-1]);
        l[i] = (i == 0 ? 0 : r[i-1]);
        ev.push_back({h[i],{l[i],r[i]}});
    }
    sort(ev.rbegin(),ev.rend());
    for(int i = 0;i < ev.size();++i)
    {
        ins(ev[i].second);
        res = (res+get_ans(ev[i].first,(i+1 == ev.size() ? 0 : ev[i+1].first)))%mod;
    }
    cout << res << "\n";
    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