Submission #569095

#	Time	Username	Problem	Language	Result	Execution time	Memory
569095		Stickfish	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	648 ms	73132 KiB

tickets

#include "tickets.h"
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
using vi = vector<int>::iterator;

pair<ll, vector<vi>> get_ans_k1(vector<pair<vi, vi>>& x) {
    int n = x.size();
    ll ans = 0;
    vector<vi> ansarr(n);
    for (int i = 0; i < n; ++i)
        ansarr[i] = x[i].first;
    for (int i = 0; i < n; ++i) {
        for (auto mdvl : {x[i].first, x[i].second}) {
            int balance = 0;
            vector<pair<ll, int>> balance_up;
            vector<pair<ll, int>> balance_down;
            ll cans = 0;
            vector<vi> cansarr(n);
            cansarr[i] = mdvl;
            for (int j = 0; j < n; ++j) {
                if (j == i)
                    continue;
                if (*x[j].first <= *mdvl && *x[j].second >= *mdvl) {
                    ll add1 = *mdvl - *x[j].first;
                    ll add2 = *x[j].second - *mdvl;
                    if (add1 < add2) {
                        cansarr[j] = x[j].second;
                        balance_down.push_back({add2 - add1, j});
                        ++balance;
                    } else {
                        cansarr[j] = x[j].first;
                        balance_up.push_back({add1 - add2, j});
                        --balance;
                    }
                } else if (*x[j].first >= *mdvl) {
                    ++balance;
                    cansarr[j] = x[j].second;
                } else {
                    --balance;
                    cansarr[j] = x[j].first;
                }
            }
            if (balance - 2 * int(balance_down.size()) > 1 || balance + 2 * int(balance_up.size()) < -1)
                continue;
            if (balance > 1) {
                sort(balance_down.rbegin(), balance_down.rend());
                while (balance_down.size() && balance > 1) {
                    int j = balance_down.back().second;
                    cansarr[j] = x[j].first;
                    balance -= 2;
                    balance_down.pop_back();
                }
            } else if (balance < -1) {
                sort(balance_up.rbegin(), balance_up.rend());
                while (balance_up.size() && balance < -1) {
                    int j = balance_up.back().second;
                    cansarr[j] = x[j].second;
                    balance += 2;
                    balance_up.pop_back();
                }
            }
            cans = 0;
            for (int j = 0; j < n; ++j)
                cans += abs(*mdvl - *cansarr[j]);
            if (cans > ans) {
                ans = cans;
                ansarr = cansarr;
            }
        }
    }
    return {ans, ansarr};
    return {};
}

ll find_maximum(int k, vector<vector<int>> x) {
    int n = x.size();
    int m = x[0].size();
    vector<vector<int>> ansarr(n, vector<int>(m, -1));
    ll ans = 0;
    if (m == 1) {
        vector<int> v;
        for (int i = 0; i < n; ++i) {
            ansarr[i][0] = 0;
            v.push_back(x[i][0]);
        }
        sort(v.begin(), v.end());
        int d = v[n / 2];
        for (int i = 0; i < n; ++i)
            ans += abs(d - v[i]);
    } else if (n * k <= 100000000) {
        vector<pair<vi, vi>> t(n);
        for (int i = 0; i < n; ++i) {
            t[i] = {x[i].begin(), x[i].end() - 1};
        }
        for (int qr = 0; qr < k; ++qr) {
            auto [ca, cu] = get_ans_k1(t);
            ans += ca;
            for (int i = 0; i < n; ++i) {
                if (t[i].first == cu[i])
                    ++t[i].first;
                else
                    --t[i].second;
                ansarr[i][cu[i] - x[i].begin()] = qr;
            }
        }
    }
    allocate_tickets(ansarr);
    return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10