Submission #130559

#	Time	Username	Problem	Language	Result	Execution time	Memory
130559		KieranHorgan	Aliens (IOI16_aliens)	C++17	25 / 100	30 ms	2376 KiB

aliens

#pragma GCC optimize("Ofast")
#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;

// #define int long long

vector<pair<int, int>> intervals;
int cost(int i, int l) {
  int overlap = max(0, intervals[l].second-intervals[l+1].first+1);
  return (intervals[i].second-intervals[l+1].first+1)*(intervals[i].second-intervals[l+1].first+1) - overlap*overlap;
}
signed n;
vector<vector<int>> dp, opt;
int j;
void recurse(int l, int r) {
  if(l==r) return;
  int i = (l+r)/2;
  for(int cur = opt[j][l-1]; cur < (r==n+1?i:opt[j][r]+1); cur++) {
    if(dp[j-1][cur] + cost(i, cur) < dp[j][i]) {
      opt[j][i] = cur;
      dp[j][i] = dp[j-1][cur] + cost(i, cur);
    }
  }
  if(l+1 != r) {
    recurse(l, i);
    recurse(i+1, r);
  }
}

long long take_photos(signed N, signed m, signed k, vector<signed> r, vector<signed> c) {
  n=N;
  for(int i = 0; i < n; i++) {
    if(c[i] >= r[i])
      intervals.push_back({r[i], -c[i]});
    else
      intervals.push_back({c[i], -r[i]});
  }
  sort(intervals.begin(), intervals.end());

  auto interStore = intervals;
  intervals.clear();
  intervals.push_back({-1, -1});
  int ma = -1;
  for(auto p: interStore) {
    if(-p.second > ma) {
      ma = -p.second;
      intervals.push_back({p.first, -p.second});
    }
  }


  n = intervals.size()-1;
  k = min(k, n);

  dp.assign(k+1, vector<int>(n+1, 1<<30));
  opt.assign(k+1, vector<int>(n+1, 0));
  dp[0][0] = 0;

  // queue<pair<int, int>> ranges;
  for(j = 1; j <= k; j++) {
    recurse(1ll, (int)n+1);
  }

  return dp[k][n];
}

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