Submission #1249305

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249305		Geforgs	Discharging (NOI20_discharging)	C++20	100 / 100	63 ms	16800 KiB

Discharging

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;

struct Line{
    ll k=0, b=0;
};

void solve(){
    ll n, i, x, res=0;
    cin>>n;
    vector<pair<ll, ll>> a;
    cin>>x;
    a.pb({x, 1});
    for(i=1;i<n;++i){
        cin>>x;
        if(a.back().first >= x){
            ++a.back().second;
        }else{
            a.pb({x, 1});
        }
    }
    Line cur, next, prev1, prev2;
    cur.k = n;
    cur.b = 0;
    vector<ll> dp(a.size());
    deque<Line> q;
    for(i=0;i<a.size();++i){
        while(!q.empty()){
            if(cur.k*a[i].first + cur.b >= q.front().k*a[i].first + q.front().b){
                cur = q.front();
                q.pop_front();
            }else{
                break;
            }
        }
        n -= a[i].second;
        dp[i] = cur.k*a[i].first + cur.b;
        next.k = n;
        next.b = dp[i];
        while(!q.empty()){
            if(q.size() == 1){
                prev1 = q.back();
                prev2 = cur;
                q.pop_back();
            }else{
                prev1 = q.back();
                q.pop_back();
                prev2 = q.back();
            }
            if((prev1.b - prev2.b)*(prev1.k - next.k) < (next.b - prev1.b)*(prev2.k - prev1.k)){
                q.pb(prev1);
                break;
            }
        }
        q.pb(next);
    }
    cout<<dp.back()<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    srand(time(nullptr));
    ll t=1;
//    cin>>t;
    for(;t>0;--t){
        solve();
    }
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 25 / 25
• Subtask 4: 11 / 11
• Subtask 5: 14 / 14
• Subtask 6: 28 / 28