Submission #800214

#	Time	Username	Problem	Language	Result	Execution time	Memory
800214		PixelCat	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	564 ms	93768 KiB

tickets

#include "tickets.h"

#ifdef NYAOWO
#include "grader.cpp"
#endif

#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
#define int LL
using namespace std;
using i32 = int32_t;
using LL = long long;
using pii = pair<int, int>;

const int MAXN = 1500;
const int INF = 1e18;

struct Ayaya {
    int val, i, j;
    Ayaya(int _val, int _i, int _j): val(_val), i(_i), j(_j) {}
    bool operator<(const Ayaya &rhs) const {
        return val < rhs.val;
    }
    bool operator>(const Ayaya &rhs) const {
        return val > rhs.val;
    }
};

int find_maximum(i32 _k, vector<vector<i32>> x) {
    int k = _k;
    int n = sz(x);
    int m = sz(x[0]);
    vector<vector<i32>> answer(n, vector<i32>(m, -1));
    vector<vector<int>> cost(n, vector<int>(k + 1, 0));

    int tot = 0;
    For(i, 0, n - 1) {
        For(j, 0, k - 1) cost[i][0] -= x[i][j];
        For(j, 1, k) cost[i][j] = cost[i][j - 1] + x[i][k - j] + x[i][m - j];
        tot += cost[i][k];
        Forr(j, k, 1) cost[i][j] -= cost[i][j - 1];
    }

    vector<int> le(n, k), ri(n);
    priority_queue<Ayaya> pq;
    For(i, 0, n - 1) {
        pq.emplace(-cost[i][k], i, k - 1);
    }
    For(_, 1, n * k / 2) {
        auto aya = pq.top(); pq.pop();
        tot += aya.val;
        le[aya.i] = aya.j;
        if(aya.j > 0) {
            pq.emplace(-cost[aya.i][aya.j], aya.i, aya.j - 1);
        }
    }
    For(i, 0, n - 1) {
        ri[i] = m - le[i];
        le[i] = k - le[i] - 1;
    }
    
    // contruct answer
    For(i, 0, k - 1) {
        int cl = n / 2, cr = n / 2;
        vector<int> vis(n, 0);
        For(j, 0, n - 1) {
            if(le[j] < 0) {
                answer[j][ri[j]] = (i32) i;
                ri[j]++;
                cr--;
                vis[j] = 1;
            } else if(ri[j] >= m) {
                answer[j][le[j]] = (i32) i;
                le[j]--;
                cl--;
                vis[j] = 1;
            }
        }
        For(j, 0, n - 1) if(!vis[j]) {
            if(cl) {
                answer[j][le[j]] = (i32) i;
                le[j]--;
                cl--;
            } else {
                answer[j][ri[j]] = (i32) i;
                ri[j]++;
                cr--;
            }
        }
    }

    allocate_tickets(answer);
    return tot;
}

• 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