Submission #637665

#	Time	Username	Problem	Language	Result	Execution time	Memory
637665		ggoh	Aliens (IOI16_aliens)	C++14	25 / 100	2052 ms	94468 KiB

aliens

#include "aliens.h"
#include<bits/stdc++.h>
using namespace std;
#define sz(v) ((int)(v).size())
typedef long long lint;
typedef pair<int,int> pii;

vector<pii>Vtmp,V;
lint sq(int L)
{
  return 1ll*L*L;
}
int a[100004],b[100004];
struct Line{
  lint a,b;
};
lint take_photos(int n, int m, int K, std::vector<int> r, std::vector<int> c) {
  lint D[n+1][K+1];
  for(int i=0;i<n;i++)
  {
    if(r[i]<c[i])swap(r[i],c[i]);
    Vtmp.push_back({r[i],-c[i]});
  }
  sort(Vtmp.begin(),Vtmp.end());
  int mini=1e9;
  for(int i=sz(Vtmp)-1;i>=0;i--)
  {
    if(mini>-Vtmp[i].second)V.push_back({Vtmp[i].first,-Vtmp[i].second});
    mini=min(mini,-Vtmp[i].second);
  }
  sort(V.begin(),V.end());
  n=sz(V);
  for(int i=1;i<=n;i++)
  {
    a[i]=V[i-1].second;
    b[i]=V[i-1].first+1;
  }
  for(int i=0;i<=n;i++)for(int k=0;k<=K;k++)D[i][k]=1e18;
  int piv=0;
  vector<Line>CHT[4004];
  CHT[0].push_back({-2*a[1],0});
  D[0][0]=0;
  for(int k=1;k<=K;k++)
  {
    for(int i=1;i<=n;i++)
    {
      for(int j=0;j<i;j++)
      {
        D[i][k]=min(D[i][k],D[j][k-1]+sq(b[i]-a[j+1])-sq(b[j]-min(b[j],a[j+1])));
      }
      //CHT[k].push_back({-2*a[i+1],D[i][k]+sq(a[i+1])-sq(b[i]-min(b[i],a[i+1]))});
    }
  }
  lint ans=1e18;
  for(int k=1;k<=K;k++)ans=min(ans,D[n][k]);
  return ans;
}

Compilation message (stderr)

aliens.cpp: In function 'lint take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:39:7: warning: unused variable 'piv' [-Wunused-variable]
   39 |   int piv=0;
      |       ^~~

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