Submission #653259

#	Time	Username	Problem	Language	Result	Execution time	Memory
653259		HuyQuang_re_Zero	Split the sequence (APIO14_sequence)	C++14	71 / 100	50 ms	131072 KiB

sequence

#include <bits/stdc++.h>
#define db long long
#define N 100002
using namespace std;
struct pt { db A,B; int vt; };
struct ps { long long tu,mau; };
ps giao(pt x,pt y)
{
    long long tu=y.B-x.B,mau=x.A-y.A;
 //   if(tu==0 && mau==0) cerr<<1<<'\n';
    if(mau<0) { tu=-tu; mau=-mau; }
    return { tu,mau };
}
bool operator < (ps a,ps b)
{
    if(a.tu<0)
    {

        if(b.tu>=0) return 1;
        a.tu=-a.tu; b.tu=-b.tu;
        //return ;
        swap(a,b);
    }
    if(b.tu<0)
    {
        if(a.tu>=0) return 0;
        a.tu=-a.tu; b.tu=-b.tu;
        swap(a,b);
       // return b<a;
    }
    return a.tu*b.mau<a.mau*b.tu;
}
pt st[N];
long long g[N],f[N][202];
int i,j,n,sl,top,k,tr[N][202],d[N];
int main()
{
 //   freopen("ntu.inp","r",stdin);
  //  freopen("ntu.out","w",stdout);
    cin>>n>>k; k++;
    for(i=0;i<=n;i++)
        for(j=0;j<=k;j++) f[i][j]=-1;
    f[0][0]=0;
    for(i=1;i<=n;i++) { cin>>g[i]; g[i]+=g[i-1]; }
    for(sl=1;sl<=k;sl++)
    {
        top=0; j=1;
      //  int ch=sl%2;
        for(i=0;i<=n;i++)
        {
            if(top>0)
            {
                j=min(j,top);
                while(j<top && st[j].A*g[i]+st[j].B<=st[j+1].A*g[i]+st[j+1].B) j++;
                f[i][sl]=st[j].A*g[i]+st[j].B;
                tr[i][sl]=st[j].vt;
                //if(sl==2 && i==n) cerr<<top<<" "<<st[j].vt<<'\n';
            }
            if(f[i][sl-1]>-1)
            {
                db A=g[i],B=f[i][sl-1]-g[i]*g[i];
                while(top>0 && A==st[top].A) top--;
                while(top>=2 && giao({ A,B,i },st[top-1])<giao(st[top],st[top-1])) top--;
                st[++top]={ A,B,i };
            }
           // cerr<<i<<" "<<sl-1<<" "<<top<<'\n';
         //  cerr<<f[i][sl]<<" "<<top<<" "<<i<<" "<<sl<<'\n';*/
        // for(j=0;j<i;j++)
          //  if(f[j][sl-1]>-1) f[i][sl]=max(f[i][sl],f[j][sl-1]+(g[i]-g[j])*g[j]);*/
        }
    }
    cout<<f[n][k]<<'\n';
    i=n;
    while(k>0)
    {
        d[i]=1;
        i=tr[i][k]; k--;
    }
    for(i=1;i<n;i++)
        if(d[i]==1) cout<<i<<" ";
    cout<<'\n';
}

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