Submission #546734

#	Time	Username	Problem	Language	Result	Execution time	Memory
546734		krit3379	Split the sequence (APIO14_sequence)	C++14	100 / 100	1096 ms	96048 KiB

sequence

#include<bits/stdc++.h>
using namespace std;
#define N 100005

struct line{
    long long m,c;
    int i;
    long long val(long long x){return m*x+c;}
    long long inter(line l){return floor((long double)(c-l.c)/(l.m-m));}
};

long long a[N],ans;
int p[N][205],now;
vector<int> cut;
deque<line> dq[205];

int main(){
    int n,k,i,j;
    scanf("%d %d",&n,&k);
    for(i=1;i<=n;i++)scanf("%lld",&a[i]),a[i]+=a[i-1];
    dq[0].push_back({0,0,0});
    for(i=1;i<n;i++){
        for(j=k;j>0;j--){
            if(dq[j-1].empty())continue;
            while(dq[j-1].size()>=2&&dq[j-1].back().val(a[n]-a[i])<=dq[j-1][dq[j-1].size()-2].val(a[n]-a[i]))dq[j-1].pop_back();
            long long v=dq[j-1].back().val(a[n]-a[i])+a[i]*(a[n]-a[i]);
            if(v>=ans&&j==k)ans=v,now=i;
            p[i][j]=dq[j-1].back().i;
            line l={-a[i],v,i};
            while(dq[j].size()>=2&&dq[j][0].inter(dq[j][1])<=dq[j][0].inter(l))dq[j].pop_front();
            dq[j].push_front(l);
        }
    }
    while(k){
        cut.push_back(now);
        now=p[now][k--];
    }
    printf("%lld\n",ans);
    for(auto x:cut)printf("%d ",x);
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     scanf("%d %d",&n,&k);
      |     ~~~~~^~~~~~~~~~~~~~~
sequence.cpp:20:27: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     for(i=1;i<=n;i++)scanf("%lld",&a[i]),a[i]+=a[i-1];
      |                      ~~~~~^~~~~~~~~~~~~~

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