Submission #576770

#	Time	Username	Problem	Language	Result	Execution time	Memory
576770		SlavicG	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	814 ms	54260 KiB

tickets

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

#define ll long long
#define sz(a) (int)a.size()
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define forn(i, n) for(int i=0;i < n; ++i)

long long find_maximum(int k, std::vector<std::vector<int>> x) {
    int n = x.size(), m = x[0].size();
    std::vector<std::vector<int>> answer(n, vector<int>(m, -1));
    vector<int> use_left(n, 0), r(n, m - 1);
    set<pair<int, int>> s;

    ll ans = 0;
    for(int i = 0; i < n; ++i) {
        s.insert({x[i][0] + x[i][m - k], i});
    }

    for(int t = 0; t < n * k / 2; ++t) {
        int i = (*s.begin()).second; s.erase(s.begin());
        if(++use_left[i] < k) {
            s.insert({x[i][use_left[i]] + x[i][m - k + use_left[i]], i});
        }
    }

    for(int kk = 0; kk < k; ++kk) {
        vector<pair<int, int>> a;
        for(int i = 0; i < n; ++i) a.pb({use_left[i], i});
        sort(rall(a));
        for(int j = 0; j < n / 2; ++j) {
            int i = a[j].second;
            assert(use_left[i]);
            ans -= x[i][use_left[i] - 1];
            answer[i][--use_left[i]] = kk;
        }
        for(int j = n / 2; j < n; ++j) {
            int i = a[j].second;
            ans += x[i][r[i]];
            answer[i][r[i]--] = kk;
        }
    }

    allocate_tickets(answer);
    return ans;
}

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