Submission #95380

#	Time	Username	Problem	Language	Result	Execution time	Memory
95380		LittleFlowers__	Split the sequence (APIO14_sequence)	C++14	100 / 100	1128 ms	85372 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second.first
#define rd second.second
#define mp(a,b,c) make_pair(a,make_pair(b,c))
using ii = pair<long long,pair<long long,int>>;

const int N=100010;
int n,k,it;
long long ma;
int a[N];
long long s[N],x[N];
vector<int> ans;

int cur;
int P[210][N];
long long F[N],H[N];
ii st[N];
double G[N];

double I(ii u,ii v){return 1.0*(v.se-u.se)/(u.fi-v.fi);}
main()
{
    ios_base::sync_with_stdio(false),cin.tie(nullptr);
    cin>>n>>k;
    for(int i=1;i<=n;++i) cin>>a[i],s[i]=s[i-1]+a[i];
    for(int i=1;i<=n;++i) x[i]=s[n]-s[i];
    for(int c=1;c<=k;++c)
    {
        cur=0;
        for(int i=c;i<n;++i)
        {
            ii T=mp(-s[i-1],H[i-1],i-1);
            if(cur && st[cur].fi==T.fi) cur--;
            while(cur>=2 && G[cur]<=I(st[cur],T)) cur--;
            st[++cur]=T;
            G[cur]=I(st[cur],st[cur-1]);

            int l=2,m,r=cur,o=1;
            while(l<=r)
            {
                m=(l+r)/2;
                if(G[m]>=x[i]) o=m,l=m+1;
                else r=m-1;
            }
            F[i]=(st[o].fi+s[i])*x[i] + st[o].se;
            P[c][i]=st[o].rd;
        }
        for(int i=c;i<n;++i) H[i]=F[i];
    }
    for(int i=k;i<n;++i) if(ma<=F[i]) ma=F[i],it=i;
    for(;k>0;k--) ans.push_back(it),
                  it=P[k][it];
    cout<<ma<<"\n";
    reverse(ans.begin(),ans.end());
    for(auto i:ans) cout<<i<<" ";
}

Compilation message (stderr)

sequence.cpp:23:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^

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