Submission #900511

#	Time	Username	Problem	Language	Result	Execution time	Memory
900511		nguyentunglam	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	514 ms	76276 KiB

tickets

#include<bits/stdc++.h>
#include "tickets.h"
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;

#ifdef ngu
void allocate_tickets(vector<vector<int> > x) {
  for(auto &i : x) {
    for(auto &j : i) cout << j << " "; cout << endl;
  }
}
#endif // ngu

long long find_maximum (int k, vector<vector<int> > x) {
  int n = x.size();
  int m = x[0].size();
  vector<int> l(n + 2), r(n + 2);
  vector<vector<int> > answer(n, vector<int> (m));
  long long ans = 0;
  priority_queue<pair<int, int> > q;
  for(int i = 0; i < n; i++) {
    l[i] = k - 1; r[i] = m - 1;
    for(int j = 0; j < k; j++) ans -= x[i][j];
    q.push({x[i][r[i]] + x[i][l[i]], i});
  }

  for(int loop = 1; loop <= n / 2 * k; loop++) {
    assert(q.size() >= 1);
    int cost, i; tie(cost, i) = q.top(); q.pop();
    ans += cost;
    l[i]--; r[i]--;
    if (l[i] >= 0) q.push({x[i][r[i]] + x[i][l[i]], i});
  }

  vector<int> order(n);

  for(int i = 0; i < n; i++) {
    r[i]++;
    order[i] = i;
  }

  int mn = 1e9, mx = -1e9;

  for(int i = 0; i < n; i++) {
    if (l[i] >= 0) mx = max(mx, x[i][l[i]]);
    if (r[i] < m) mn = min(mn, x[i][r[i]]);
  }

  assert(mx <= mn);

  for(int i = 0; i < n; i++) for(int j = 0; j < m; j++) answer[i][j] = -1;

  for(int round = 0; round < k; round++) {
    sort(order.begin(), order.begin() + n, [&] (const int &x, const int &y) {
      return r[x] < r[y];
         });
    for(int cur = 0; cur < n / 2; cur++) {
      int i = order[cur];
      assert(r[i] < m);
      answer[i][r[i]] = round;
      r[i]++;
    }
    for(int cur = n / 2; cur < n; cur++) {
      int i = order[cur];
      assert(l[i] >= 0);
      answer[i][l[i]] = round;
      l[i]--;
    }
  }
  allocate_tickets(answer);
  return ans;
}

#ifdef ngu
int main() {

  freopen ("task.inp", "r", stdin);
  freopen ("task.out", "w", stdout);

  int n, m, k; cin >> n >> m >> k;

  vector<vector<int> > x(n, vector<int> (m));

  for(int i = 0; i < n; i++) for(int j = 0; j < m; j++) cin >> x[i][j];

  cout << find_maximum(k, x);
}
#endif // ngu

• 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