Submission #837086

#	Time	Username	Problem	Language	Result	Execution time	Memory
837086		erdemkiraz	Aliens (IOI16_aliens)	C++17	0 / 100	1 ms	340 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair<int, int> ii;
 
const int M = 1e6 + 5;
 
int n, m, k;
int at[M];

vector<int> ats;
vector<ii> v;
 
vector<vector<vector<ll>>> dp;
 
ll f(int x, int last, int k) {
  if(x >= m) {
    return 0;
  }
 
  ll &r = dp[x][last][k];
  if(r != -1) {
    return r;
  }
 
  r = 1e18;
 
  if(ats[last] >= ats[v[x].second]) {
    r = min(r, f(x + 1, last, k));
  }
 
  if(k) {
    int mx = v[x].second;
    for(int y = x + 1; y < m; y++) {
      if(ats[mx] <= ats[last]) {
        continue;
      }

      ll len = ats[mx] - v[x].first;
      ll prev_len = max(0, ats[last] - v[x].first);
      r = min(r, f(x + 1, mx, k - 1) + len * len - prev_len * prev_len);

      mx = max(mx, v[y].second);
    }
  }
 
  return r;
}
 
ll take_photos(int nn, int mm, int kk, vector<int> r, vector<int> c) {
  n = nn;
  m = mm;
  k = kk;
 
  for(int i = 0; i < n; i++) {
    if(r[i] > c[i]) {
      swap(r[i], c[i]);
    }
    at[r[i] + 1] = max(at[r[i] + 1], c[i] + 2);
  }

  ats.push_back(0);

  for(int i = 1; i <= m + 1; i++) {
    if(at[i]) {
      ats.push_back(at[i]);
    }
  }

  sort(ats.begin(), ats.end());
  ats.resize(unique(ats.begin(), ats.end()) - ats.begin());

  for(int i = 1; i <= m; i++) {
    at[i] = lower_bound(ats.begin(), ats.end(), at[i]) - ats.begin();
    v.push_back({i, at[i]});
  }

  m = (int) v.size();
 
  dp.resize(m + 1, vector<vector<ll>>((int) ats.size() + 1, vector<ll>(k + 1, -1)));
 
  ll ans = f(0, 0, k);
 
  return ans;
}

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