Submission #770570

#	Time	Username	Problem	Language	Result	Execution time	Memory
770570		bleahbleah	Carnival Tickets (IOI20_tickets)	C++17	90 / 100	1857 ms	2097152 KiB

tickets

#include <bits/stdc++.h>
#include "tickets.h"
#define all(x) (x).begin(),(x).end()
using namespace std;


using ll = long long;
using ld = long double;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 1500 + 5;

void partition(int k, vector<vector<int>> wsign) {
  int n = sz(wsign), m = sz(wsign[0]);
  vector<pii> freq(n, pii{0, 0});
  vector<deque<int>> sorted(n);
  vector<vector<int>> rez(n, vector<int>(m, -1));
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < m; j++) if(wsign[i][j] == -1) sorted[i].emplace_back(j), freq[i].first++;
    for(int j = 0; j < m; j++) if(wsign[i][j] ==  1) sorted[i].emplace_back(j), freq[i].second++;      
  } 
  for(int Q = 0; Q < k; Q++) {
    vector<int> checked(n);
    
    vector<int> atr(n);
    iota(all(atr), 0);
    sort(all(atr), [&](auto a, auto b) { return freq[a].first > freq[b].first; });
    
    for(int T = 0, cnt = 0; cnt < n / 2 && T < n; T++) {
      int i = atr[T];
      if(checked[i]) continue;
      if(freq[i].first > 0) {
        rez[i][sorted[i].front()] = Q;
        sorted[i].pop_front();
        cnt++;
        checked[i] = 1;
        freq[i].first--;
      }
    }
    sort(all(atr), [&](auto a, auto b) { return freq[a].second > freq[b].second; });
    for(int T = 0, cnt = 0; cnt < n / 2 && T < n; T++) {
      int i = atr[T];
      if(checked[i]) continue;
      if(freq[i].second > 0) {
        rez[i][sorted[i].back()] = Q;
        sorted[i].pop_back();
        cnt++;
        checked[i] = 1;
        freq[i].second--;
      }
    }
  }
  
  allocate_tickets(rez);
  return;
}

const ll infll = 1e18 + 5;
const int nnmax = 300 + 5;
ll S2(int k, vector<vector<int>> d) {
  int n = sz(d), m = sz(d[0]);
  vector<vector<ll>> dp(n + 1, vector<ll>(k * n / 2 + 2, -infll));
  vector<vector<int>> with(n + 1, vector<int>(k * n / 2 + 2, 0));
  reverse(all(d));
  d.emplace_back(vector<int>());
  reverse(all(d));
  //for(int j = 1; j < sz(dp[0]); j++) dp[0][j] = -infll;
  dp[0][0] = 0;
  for(int i = 1; i <= n; i++) {
    vector<int> tmp = d[i];
    sort(all(tmp));
    vector<ll> cost(k + 1);
    ll tmpsum = 0;
    for(int i = 0; i < k; i++) {
      tmpsum += tmp[i];
      cost[i + 1] -= tmpsum;
    }
    tmpsum = 0;
    for(int i = 0, j = sz(tmp) - 1; i < k; i++, j--) {
      tmpsum += tmp[j];
      cost[k - i - 1] += tmpsum;
    }
    int lim = min(k * n / 2, i * k);
    for(int j = 0; j <= lim; j++) {
      int mnw = 0;
      dp[i][j] = -infll;
      for(int minus = 0; minus <= min(j, k); minus++) {
        if(dp[i - 1][j - minus] + cost[minus] > dp[i][j]) {
          mnw = minus;
          dp[i][j] = dp[i - 1][j - minus] + cost[minus];
        }
      }
      with[i][j] = mnw;
      //cerr << dp[i][j] << ' ';
    }
    //cerr << '\n';
  }
  //cerr << "finished\n";
  int current = n / 2 * k;
  vector<vector<int>> wsign(n, vector<int>(m, 0));
  for(int i = n; i > 0; i--) {
    vector<int> atr(m);
    iota(all(atr), 0);
    sort(all(atr), [&](int a, int b) { return d[i][a] < d[i][b]; });
    //cerr << sz(with[i]) << ' ' << current << '\n';
    int u = with[i][current];
    current -= u;
    //cerr << u << '\n';
    for(int j = 0; j < u; j++)
      //cerr << atr[j] << '\n',
      wsign[i - 1][atr[j]] = -1;
    for(int j = m - 1, t = 0; t < k - u; t++, j--)
      //cerr << atr[j] << '\n',
      wsign[i - 1][atr[j]] = 1;
  }
  //cerr << current << '\n';
  partition(k, wsign);
  //cerr << "better\n";
  ll sum = 0;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < m; j++)
      //cerr << wsign[i][j] << ' ',
      sum += wsign[i][j] * d[i + 1][j];
    //cerr << '\n';
  }
  
  return sum;
}

ll S3(int k, vector<vector<int>> d) {
  int n = sz(d), m = sz(d[0]);
  vector<pii> freq(n, pii{0, 0});
  vector<deque<int>> sorted(n);
  vector<vector<int>> rez(n, vector<int>(m, -1));
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < m; j++) if(d[i][j] ==  0) sorted[i].emplace_back(j), freq[i].first++;
    for(int j = 0; j < m; j++) if(d[i][j] ==  1) sorted[i].emplace_back(j), freq[i].second++;      
  } 
  ll sum = 0;
  for(int Q = 0; Q < k; Q++) {
    vector<int> checked(n);
    
    vector<int> atr(n);
    iota(all(atr), 0);
    sort(all(atr), [&](auto a, auto b) { return freq[a].first > freq[b].first; });
    
    int total = 0;
    
    for(int T = 0, cnt = 0; cnt < n / 2 && T < n; T++) {
      int i = atr[T];
      if(checked[i]) continue;
      if(freq[i].first > 0) {
        rez[i][sorted[i].front()] = Q;
        sorted[i].pop_front();
        cnt++;
        checked[i] = 1;
        freq[i].first--;
      }
    }
    sort(all(atr), [&](auto a, auto b) { return freq[a].second > freq[b].second; });
    for(int T = 0, cnt = 0; cnt < n / 2 && T < n; T++) {
      int i = atr[T];
      if(checked[i]) continue;
      if(freq[i].second > 0) {
        total++;
        rez[i][sorted[i].back()] = Q;
        sorted[i].pop_back();
        cnt++;
        checked[i] = 1;
        freq[i].second--;
      }
    }
    
    for(int T = 0; T < n; T++) {
      int i = atr[T];
      if(checked[i]) continue;
      if(freq[i].second > 0)
        total++,
        freq[i].second--;
      else
        freq[i].first--;
      rez[i][sorted[i].back()] = Q;
      sorted[i].pop_back();
      checked[i] = 1;
    }
    
    sum += min(total, n - total);
  }
  
  allocate_tickets(rez);
  return sum;
}
 

ll S4(int k, vector<vector<int>> d) { 
  vector<pii> values;
  int n = sz(d), m = sz(d[0]);
  for(int i = 0; i < n; i++) 
    for(int j = 0; j < m; j++) 
      values.emplace_back(i, j);
  sort(all(values), [&](auto a, auto b) { return d[a.first][a.second] < d[b.first][b.second]; });
  
  vector<vector<int>> signs(n, vector<int>(m, 1));
  for(int i = 0; i < n / 2 * k; i++)
    signs[values[i].first][values[i].second] = -1;
  
  partition(k, signs);
  ll sum = 0;
  for(auto [a, b] : values) {
    sum += d[a][b] * signs[a][b];
  }
  return sum;
  
}

ll S1(int k, vector<vector<int>> d) {
  int n = sz(d), m = 1;
  vector<vector<int>> rez(n, vector<int>(m, 0));
  allocate_tickets(rez);
  vector<int> v;
  for(auto a : d)
    for(auto x : a) v.emplace_back(x);
  sort(all(v));
  ll sum = 0;
  for(int i = 0; i < n; i++)
    sum += v[i];
  for(int i = 0; i < n / 2; i++)
    sum -= 2 * v[i];
  return sum;
}

long long find_maximum(int k, std::vector<std::vector<int>> d) {
  bool ok = 1;
  for(auto a : d)
    for(auto x : a)
      ok &= (x == 0 || x == 1);
  if(ok)
    return S3(k, d);
  else if(sz(d[0]) == 1) return S1(k, d);
  else if(k == sz(d[0])) 
    return S4(k, d);
  else
    return S2(k, d);
}


/**
      Anul asta se da centroid.
-- Surse oficiale
*/

• 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: 0 / 10