Submission #957241

#	Time	Username	Problem	Language	Result	Execution time	Memory
957241		duckindog	Aliens (IOI16_aliens)	C++17	16 / 100	78 ms	2408 KiB

aliens

#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#include "aliens.h"
#endif

long long take_photos(int n, int m, int k, vector<int> r, vector<int> c) { 
  using pii = pair<int, int>;
  vector<pii> p(n);

  bool sub2 = true;
  for (int i = 0; i < n; ++i) {
    if (r[i] > c[i]) swap(r[i], c[i]);
    sub2 &= (r[i] == c[i]);
    p[i] = {r[i], c[i]};
  }

  if (n <= 50 && m <= 100 && k == n) { 
    vector<vector<bool>> mk(m, vector<bool>(m));
    for (int i = 0; i < n; ++i) { 
      auto [x, y] = p[i];
      if (x > y) swap(x, y);
      for (int i = x; i <= y; ++i) { 
        for (int j = x; j <= y; ++j) mk[i][j] = true;
      }
    }
    
    int answer = 0;
    for (int i = 0; i < m; ++i) 
      for (int j = 0; j < m; ++j) answer += mk[i][j];
    return answer;
  }

  auto dis = [&](pii a) { return abs(a.first - a.second) + 1; };

  sort(p.begin(), p.end());
  p.resize(n = unique(p.begin(), p.end()) - p.begin());
  k = min(k, n);

  sort(p.begin(), p.end(), [&](const auto& a, const auto& b) { 
    return make_pair(a.first, dis(a)) < make_pair(b.first, dis(b));
  });

  vector<vector<long long>> f(k + 1, vector<long long>(n + 1, 1e15));
  
  if (sub2) { 
    f[0][0] = 0;
    for (int i = 1; i <= k; ++i) { 
      for (int j = 1; j <= n; ++j) { 
        auto& ret = f[i][j];
        for (int t = 1; t <= j; ++t) {
          int nval = (p[j - 1].first - p[t - 1].first + 1);
          nval *= nval;
          ret = min(ret, f[i - 1][t - 1] + nval);
        }
      }
    }
    return f[k][n];
  }
  return 0;
}

#ifdef LOCAL
int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  int n, m, k; cin >> n >> m >> k;
  vector<int> r(n), c(n);
  for (int i = 0; i < n; ++i) cin >> r[i] >> c[i];

  cout << take_photos(n, m, k, r, c) << "\n";
}
#endif

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40