Submission #771258

#	Time	Username	Problem	Language	Result	Execution time	Memory
771258		cadmiumsky	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	865 ms	111008 KiB

tickets

#include <bits/stdc++.h>
#include "tickets.h"
#define all(x) (x).begin(),(x).end()
using namespace std;
#define sz(x) ((int)(x).size())
using ll = long long;
 
using pii = pair<int,int>;
 
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>> delta(n + 1);
  vector<int> mcount(n + 1, 0);
  
  reverse(all(d));
  d.emplace_back(vector<int>());
  reverse(all(d));
  
  set<pair<ll, int>> fmerge;
  ll sum = 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;
    }
    sum += cost[0];
    fmerge.emplace(cost[1] - cost[0], i);
    //cerr << i << ' ' << cost[1] - cost[0] << '\n';
    delta[i] = cost;
  }
  
  for(int i = 0; i < n / 2 * k; i++) {
    auto [c, ptr] = *fmerge.rbegin();
    //cerr << sum << " --> " << sum + c << '\t' << ptr << '\n';
    sum += c;
    fmerge.erase(*fmerge.rbegin());
    mcount[ptr]++;
    if(mcount[ptr] == k) continue;
    fmerge.emplace(delta[ptr][mcount[ptr] + 1] - delta[ptr][mcount[ptr]], ptr);
  }
  
  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]; });
    int u = mcount[i];
    for(int j = 0; j < u; j++)
      wsign[i - 1][atr[j]] = -1;
    for(int j = m - 1, t = 0; t < k - u; t++, j--)
      wsign[i - 1][atr[j]] = 1;
  }
  partition(k, wsign);
  
  return sum;
}
long long find_maximum(int k, std::vector<std::vector<int>> d) {
    return S2(k, d);
}

Compilation message (stderr)

tickets.cpp: In function 'll S2(int, std::vector<std::vector<int> >)':
tickets.cpp:98:7: warning: unused variable 'current' [-Wunused-variable]
   98 |   int current = n / 2 * k;
      |       ^~~~~~~

• 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