Submission #1238206

#	Time	Username	Problem	Language	Result	Execution time	Memory
1238206		SalihSahin	Carnival Tickets (IOI20_tickets)	C++20	27 / 100	323 ms	69124 KiB

tickets

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

const long long inf = 1e15;

long long find_maximum(int k, vector<vector<int>> x) {
    int n = x.size();
    int m = x[0].size();
    vector<vector<int>> ans(n, vector<int>(m, -1));

    if(m == 1){
        long long val = 0;
        vector<int> arr;
        for(int i = 0; i < n; i++){
            arr.pb(x[i][0]);
            val += x[i][0];

            ans[i][0] = 0;
        }
        sort(arr.begin(), arr.end());
        for(int i = 0; i < n/2; i++){
            val -= arr[i] * 2;
        }

        allocate_tickets(ans);
        return val;
    }
    else if(k == 1){
        vector<int> mini(n), maxi(n);
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                if(x[i][j] > x[i][maxi[i]]){
                    maxi[i] = j;
                }
                if(x[i][j] < x[i][mini[i]]){
                    mini[i] = j;
                }
            }
        }

        vector<vector<long long> > dp(n+1, vector<long long>(n/2+2, -inf));
        vector<vector<pair<int, int> > > par(n+1, vector<pair<int, int> >(n/2+2));
        dp[0][0] = 0;
        for(int i = 0; i < n; i++){
            for(int j = 0; j <= min(i, n/2); j++){
                if(dp[i][j] + x[i][maxi[i]] > dp[i+1][j+1]){
                    dp[i+1][j+1] = dp[i][j] + x[i][maxi[i]];
                    par[i+1][j+1] = {i, j};
                }
                if(dp[i][j] - x[i][mini[i]] > dp[i+1][j]){
                    dp[i+1][j] = dp[i][j] - x[i][mini[i]];
                    par[i+1][j] = {i, j};
                }
            }
        }

        pair<int, int> now = {n, n/2};
        while(now != make_pair(0, 0)){
            pair<int, int> nxt = par[now.first][now.second];
            if(now.second == nxt.second){
                ans[nxt.first][mini[nxt.first]] = 0;
            }
            else{
                ans[nxt.first][maxi[nxt.first]] = 0;
            }
            now = nxt;
        }

        allocate_tickets(ans);
        return dp[n][n/2];
    }

    vector<vector<long long> > dp(n+1, vector<long long>(n*k/2 + 2, -inf));
    vector<vector<pair<int, int> > > par(n+1, vector<pair<int, int> >(n*k/2+2));
    dp[0][0] = 0;
    for(int i = 0; i < n; i++){
        vector<pair<int, int> > arr;
        for(int j = 0; j < m; j++){
            arr.pb({x[i][j], j});
        }
        sort(arr.begin(), arr.end());
        vector<long long> add(k+1);
        long long now = 0;
        for(int j = 0; j <= k; j++){
            now -= arr[j].first;
        }
        add[0] = now;
        for(int j = 0; j < k; j++){
            now += arr[(k - j)].first;
            now += arr[m - j - 1].first;
            add[j+1] = now;
        }

        for(int take = 0; take <= k; take++){
            for(int j = 0; j + take <= n*k/2; j++){
                if(dp[i+1][j + take] < dp[i][j] + add[take]){
                    dp[i+1][j + take] = dp[i][j] + add[take];
                    par[i+1][j + take] = {i, j};
                }
            }
        }
    }

    int lstsm = 0, lstbg = k-1;
    pair<int, int> now = {n, n*k/2};
    while(now != make_pair(0, 0)){
        pair<int, int> nxt = par[now.first][now.second];
        int big = now.second - nxt.second;
        int small = k - big;

        vector<pair<int, int> > arr;
        for(int j = 0; j < m; j++){
            arr.pb({x[nxt.first][j], j});
        }
        sort(arr.begin(), arr.end());
        for(int i = 0; i < small; i++){
            ans[nxt.first][arr[i].second] = lstsm++;
            if(lstsm == k) lstsm -= k;
        }
        for(int i = m-1; i >= m-big; i--){
            ans[nxt.first][arr[i].second] = lstbg--;
            if(lstbg == -1) lstbg += k;
        }

        now = nxt;
    }

    allocate_tickets(ans);

    return dp[n][n*k/2] + 50;
}

• 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