Submission #288326

#	Time	Username	Problem	Language	Result	Execution time	Memory
288326		andrew	Meetings (IOI18_meetings)	C++17	19 / 100	560 ms	196476 KiB

meetings

#include <bits/stdc++.h>
#include "meetings.h"

#define fi first
#define se second
#define p_b push_back
#define m_p make_pair
#define sz(x) (int)x.size()
#define pii pair <int, int>
#define all(x) x.begin(),x.end()

using namespace std;
typedef long long ll;
const ll inf = 1e18;

struct node{
    int pref, suf, size, ans;
};

vector <node> T;

node clr;

node merge(node a, node b){
    if(a.size == 0)return b;
    if(b.size == 0)return a;
    node res;
    res.size = a.size + b.size;
    res.pref = a.pref;
    if(a.pref == a.size)res.pref = a.size + b.pref;
    res.suf = b.suf;
    if(b.suf == b.size)res.suf = b.size + a.suf;
    res.ans = max(a.ans, max(b.ans, a.suf + b.pref));
    return res;
}

void build(int v, int tl, int tr, vector <int> &H){
    if(tl == tr){
        T[v].pref = T[v].suf = T[v].ans = (H[tl] == 2);
        T[v].size = 1;
    }else{
        int tm = (tl + tr) >> 1;
        build(v << 1, tl, tm, H);
        build(v << 1 | 1, tm + 1, tr, H);
        T[v] = merge(T[v << 1], T[v << 1 | 1]);
    }
}

node get(int v, int tl, int tr, int l, int r){
    if(l > r)return clr;
    if(tl == l && tr == r)return T[v];
    int tm = (tl + tr) >> 1;
    return merge(get(v << 1, tl, tm, l, min(r, tm)), get(v << 1 | 1, tm + 1, tr, max(l, tm + 1), r));
}

vector<ll> minimum_costs(vector<int> H, vector<int> l, vector<int> r) {
    int n = sz(H), q = sz(l);
    if(n <= 5000 && q <= 5000){
        vector <ll> ans(q);
        vector < vector <ll> > pre_calc(n, vector <ll> (n, 0));
        for(int x = 0; x < n; x++){
            int mx = H[x];
            ll sc = 0;
            for(int j = x; j < n; j++){
                mx = max(mx, H[j]);
                sc += mx;
                pre_calc[x][j] = sc;
            }
            mx = H[x];
            sc = 0;
            for(int j = x; j >= 0; j--){
                mx = max(mx, H[j]);
                sc += mx;
                pre_calc[x][j] = sc;
            }
        }
        for(int i = 0; i < q; i++){
            ans[i] = pre_calc[l[i]][r[i]];
            for(int x = l[i] + 1; x <= r[i]; x++){
                ans[i] = min(ans[i], pre_calc[x - 1][l[i]] + pre_calc[x][r[i]]);
            }
        }
        return ans;
    }else{
        vector <ll> ans(q);
        T.resize(4 * n + 3);
        build(1, 0, n - 1, H);
        for(int i = 0; i < q; i++){
            ans[i] = 2 * (r[i] - l[i] + 1) - get(1, 0, n - 1, l[i], r[i]).ans;
        }
        return ans;
    }
}

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40