Submission #111129

#	Time	Username	Problem	Language	Result	Execution time	Memory
111129		aleksami	Split the sequence (APIO14_sequence)	C++14	0 / 100	75 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;
          	zzz.idx=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;
        }

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:58:17: warning: variable 'zzz' set but not used [-Wunused-but-set-variable]
            lajn zzz;
                 ^~~

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