Submission #97992

#	Time	Username	Problem	Language	Result	Execution time	Memory
97992		Bodo171	Split the sequence (APIO14_sequence)	C++14	0 / 100	24 ms	4700 KiB

sequence

#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
const int nmax=100005;
struct dreapta
{
    long long a,b;
    int wh;
}st[nmax];
long long dp[2][nmax];
int prc[205][nmax];
long long mx;
long long a[nmax],sum[nmax];
long double a1,a2,b1,b2;
int ans[nmax];
long double intersect(dreapta unu,dreapta doi)
{
    a1=unu.a;b1=unu.b;a2=doi.a;b2=doi.b;
    return (b1-b2)/(a2-a1);
}
int u,i,j,cnt,ult,n,k,use,poz_opt;
void ins(long long A,long long B,int prc)
{
    dreapta x={A,B,prc};
    if(u&&st[u].a==A&&st[u].b>=B)
        return;
    while(u&&st[u].a==A&&st[u].b<=B)
        u--;
    while(u>1&&intersect(st[u],st[u-1])>intersect(st[u-1],x))
        u--;
    st[++u]=x;
}
long long get_opt(long long x)
{
    long double pct=x;
    while(u>1&&intersect(st[u],st[u-1])>pct)
        u--;
    ult=st[u].wh;
    return (1LL*st[u].a*x+1LL*st[u].b);
}
void solve(bool rev)
{
    bool updatat=0;
    for(i=1;i<=n;i++)
        dp[0][i]=dp[1][i]=0;
    for(i=1;i<=n;i++)
        sum[i]=sum[i-1]+a[i];
    for(cnt=1;cnt<=k;cnt++)
    {
        u=0;use=1-use;
        for(i=cnt;i<n;i++)
        {
            ins(sum[i-1],dp[1-use][i-1],i-1);
            dp[use][i]=get_opt(sum[i]-sum[n])+1LL*sum[i]*sum[n]-1LL*sum[i]*sum[i];
            prc[cnt][i]=ult;
            if(cnt==k&&dp[use][i]>mx)
                mx=dp[use][i],poz_opt=i,updatat=1;
        }
    }
    if(updatat)
    {
        for(int i=1;i<=k;i++)
        {
            ans[k-i+1]=poz_opt;
            poz_opt=prc[k-i+1][poz_opt];
        }
        if(rev)
            for(i=1;i<=k;i++)
               ans[i]=(n-ans[i]+1);
    }
}
int main()
{
  //  freopen("data.in","r",stdin);
    ios_base::sync_with_stdio(false);
    cin>>n>>k;
    for(i=1;i<=n;i++)
        cin>>a[i];
    solve(0);
    reverse(a+1,a+n+1);
    //solve(1);
    cout<<mx<<'\n';
    for(i=1;i<=k;i++)
        cout<<ans[i]<<' ';
    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