Submission #111127

#	Time	Username	Problem	Language	Result	Execution time	Memory
111127		aleksami	Split the sequence (APIO14_sequence)	C++14	0 / 100	68 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];
          now.idx=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