Submission #98011

#	Time	Username	Problem	Language	Result	Execution time	Memory
98011		Bodo171	Split the sequence (APIO14_sequence)	C++14	100 / 100	1188 ms	84348 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];
int p;
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(p<=u&&st[u].a==A&&st[u].b>=B)
        return;
    while(p<=u&&st[u].a==A&&st[u].b<=B)
        u--;
    while(p<u&&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(p<u&&intersect(st[p],st[p+1])<pct)
        p++;
    ult=st[p].wh;
    return (1LL*st[p].a*x+1LL*st[p].b);
}
void solve(bool rev)
{
    bool updatat=0;
    for(i=1;i<=n;i++)
        sum[i]=sum[i-1]+a[i];
    for(cnt=1;cnt<=k;cnt++)
    {
        u=0;p=1;use=1-use;
        for(i=cnt;i<n;i++)
        {
            ins(sum[i-1],dp[1-use][i-1],i-1);
            dp[use][i]=1LL*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=1LL*dp[use][i],poz_opt=i;
        }
    }
    for(int i=1;i<=k;i++)
    {
        ans[k-i+1]=poz_opt;
        poz_opt=prc[k-i+1][poz_opt];
    }
}
int main()
{
    //freopen("data.in","r",stdin);
    ios_base::sync_with_stdio(false);
    mx=-1;
    cin>>n>>k;
    for(i=1;i<=n;i++)
        cin>>a[i];
    solve(0);
    cout<<mx<<'\n';
    for(i=1;i<=k;i++)
        cout<<ans[i]<<' ';
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'void solve(bool)':
sequence.cpp:45:10: warning: unused variable 'updatat' [-Wunused-variable]
     bool updatat=0;
          ^~~~~~~

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