Submission #723890

#	Time	Username	Problem	Language	Result	Execution time	Memory
723890		Pety	Aliens (IOI16_aliens)	C++14	25 / 100	7 ms	4260 KiB

aliens

#include <bits/stdc++.h>

using namespace std;

const long long INF = 1e18;
long long dp[502][502], cost[502][502];

void divide (int k, int st, int dr, int opl, int opr) {
  if (st > dr)
    return;
  int mid = (st + dr) / 2;
  pair<long long, int>best = {INF, -1};
  for (int i = opl; i <= min(mid, opr); i++) {
    best = min(best, {dp[k - 1][i - 1] + cost[i][mid], i});
  }
  dp[k][mid] = best.first;
  int opt = best.second;
  divide(k, st, mid - 1, opl, opt);
  divide(k, mid + 1, dr, opt, opr);
}

long long take_photos(int n, int m, int k, vector<int>r, vector<int> c) {
  vector<pair<int, int>>p, p2;
  for (int i = 0; i < n; i++) {
    if (r[i] > c[i])
      swap(r[i], c[i]);
    p.push_back({r[i], -c[i]});
  }
  sort(p.begin(), p.end());
  p2.push_back({-1, -1});
  int mx = -1;
  for (int i = 0; i < n; i++) {
    if (-p[i].second > mx)
      p2.push_back({p[i].first, -p[i].second});
    mx = max(mx, -p[i].second);
  }
  n = p2.size() - 1;
  k = min(k, n);
  for (int i = 0; i <= k; i++)
    for (int j = 0; j <= n; j++)
      dp[i][j] = INF;
  for (int j = 0; j <= k; j++)
    dp[j][0] = 0;
  for (int i = 1; i <= n; i++)
    for (int j = i, mx = 0; j <= n; j++) {
      mx = max(mx, p2[j].second);
      cost[i][j] = 1ll * (1ll * mx - p2[i].first + 1) * (mx - p2[i].first + 1) - (i > 1 ? max(0, p2[i - 1].second - p2[i].first + 1) * max(0, p2[i - 1].second - p2[i].first + 1) : 0);
    }
  for (int j = 1; j <= n; j++)
    dp[1][j] = cost[1][j];
  for (int i = 2; i <= k; i++) {
    divide(i, 1, n, 1, n);
  }
  return dp[k][n];
}

// int main() {
//     int n, m, k;
//     assert(3 == scanf("%d %d %d", &n, &m, &k));


//     std::vector<int> r(n), c(n);
//     for (int i = 0; i < n; i++) {
//         assert(2 == scanf("%d %d", &r[i], &c[i]));
//     }
//     long long ans = take_photos(n, m, k, r, c);
    
    
//     printf("%lld\n", ans);
//     return 0;
// }

/**
 5 7 2
 0 3
 4 4
 4 6
 4 5
 4 6
  
*/

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