Submission #1032985

#	Time	Username	Problem	Language	Result	Execution time	Memory
1032985		Zicrus	Carnival Tickets (IOI20_tickets)	C++17	41 / 100	333 ms	82000 KiB

tickets

#include <bits/stdc++.h>
#include "tickets.h"
using namespace std;

typedef long long ll;

ll sub1and2(int k, vector<vector<int>> x) {
    ll n = x.size(), m = x[0].size();
    vector<vector<int>> res(n, vector<int>(m, -1));
    ll sum = 0;
    vector<ll> front(n, 0), back(n, m-1);

    while (k--) {
        vector<pair<ll, ll>> avgId(n);
        for (int i = 0; i < n; i++) {
            avgId[i] = {x[i][front[i]] + x[i][back[i]], i};
        }
        sort(avgId.begin(), avgId.end());
        vector<ll> choices(n);
        ll median = 0;
        for (int i = 0; i < n/2; i++) {
            choices[i] = x[avgId[i].second][front[avgId[i].second]];
            res[avgId[i].second][front[avgId[i].second]] = k;
            front[avgId[i].second]++;
            median = max(median, choices[i]);
        }
        for (int i = n/2; i < n; i++) {
            choices[i] = x[avgId[i].second][back[avgId[i].second]];
            res[avgId[i].second][back[avgId[i].second]] = k;
            back[avgId[i].second]--;
        }
        for (auto &e : choices) sum += abs(e - median);
    }

    allocate_tickets(res);
    return sum;
}

ll sub3(int k, vector<vector<int>> x) {
    ll n = x.size(), m = x[0].size();
    vector<vector<int>> res(n, vector<int>(m, -1));
    ll sum = 0;
    vector<ll> front(n, 0), back(n, m-1);

    vector<pair<ll, ll>> cnt(n);
    for (int i = 0; i < n; i++) {
        cnt[i].first = lower_bound(x[i].begin(), x[i].end(), 1) - x[i].begin();
        cnt[i].second = i;
    }
    sort(cnt.begin(), cnt.end());

    while (k--) {
        ll temp = 0;
        for (int i = 0; i < n/2; i++) {
            res[cnt[i].second][back[cnt[i].second]] = k;
            if (x[cnt[i].second][back[cnt[i].second]]) temp++;
            else {
                temp--;
                cnt[i].first--;
            }
            back[cnt[i].second]--;
        }
        for (int i = n/2; i < n; i++) {
            res[cnt[i].second][front[cnt[i].second]] = k;
            if (x[cnt[i].second][front[cnt[i].second]]) temp++;
            else {
                temp--;
                cnt[i].first--;
            }
            front[cnt[i].second]++;
        }
        sum += n/2 - abs(temp)/2;
        sort(cnt.begin(), cnt.end());
    }
    
    allocate_tickets(res);
    return sum;
}

ll find_maximum(int k, vector<vector<int>> x) {
    if (k == 1) return sub1and2(k, x);
    return sub3(k, x);
}

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