Submission #111126

#	Time	Username	Problem	Language	Result	Execution time	Memory
111126		aleksami	Split the sequence (APIO14_sequence)	C++14	0 / 100	48 ms	8660 KiB

sequence

#include <bits/stdc++.h>

using namespace std;
typedef long double ll;
#define MAXN 100005
#define MAXK 205
const ll INF = 1e18;
ll dp[MAXN][MAXK];
ll a[MAXN];
int opt[MAXN][MAXK];
struct lajn
{
  ll k;
  ll n;
  int idx;
};
ll eval(lajn l,ll x){return l.k*x+l.n;}
ll presekx(lajn a,lajn b)
{
  if(a.k==b.k)return INF;
  return 1.00*(a.n-b.n)/(b.k-a.k);
}
deque <lajn> q;
lajn next_front()
{
  lajn z = q.front();
  q.pop_front();
  lajn o = q.front();
  q.push_front(z);
  return o;
}
lajn next_back()
{
  lajn z = q.back();
  q.pop_back();
  lajn o = q.back();
  q.push_back(z);
  return o;
}

int main()
{
  ios_base::sync_with_stdio(false);
  int n,k;
  cin >> n >> k;
  for(int i = 1; i <= n; i++)cin >> a[i],a[i]+=a[i-1];
  for(int i = 1; i <= n; i++)
  {
    for(int j = 1; j <= k; j++)
    {
      dp[j][i]=-INF;
    }
  }
  for(int i = 1; i <= n; i++)dp[0][i]=0LL;
  for(int i = 1; i <= k; i++)
  {
  	q.clear();
  	lajn zzz;
  	zzz.k=0;
  	zzz.n=0;
  	q.push_front(zzz);
    for(int j = 1; j <= n; j++)
    {
      while(q.size()>1 && presekx(q.front(),next_front())<=a[j])q.pop_front();
      if(q.size())dp[i][j]=q.front().k*a[j]+q.front().n,opt[i][j]=q.front().idx;
      lajn now;
      now.k=a[j];
      now.n=-a[j]*a[j]+dp[i-1][j];
      while(q.size()>2 && presekx(next_back(),q.front())>=presekx(q.front(),now))q.pop_back();
      q.push_back(now);
    }
  }
  cout << dp[k][n] << "\n";
  int now = n;
  while(k>0)
  {
    cout << opt[k][now] << " ";
    now=opt[k][now];
    k--;
  }
  return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29