Submission #983079

#	Time	Username	Problem	Language	Result	Execution time	Memory
983079		Hugo1729	Split the sequence (APIO14_sequence)	C++11	71 / 100	72 ms	131072 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define f first
#define s second
 
ll dp[200001][402]={0};
ll pref[200001]={0};
ll p[200001][402]={0};

struct line{
    ll m, c;

    line(ll _m, ll _c){m=_m;c=_c;};

    ll operator() (ll x){return x*m+c;};
};
 
int main(){
    // cin.tie(0)->sync_with_stdio(0);
 
    int n, k; cin >> n >> k;
    vector<ll> a(n);
    for(int i=0;i<n;i++)cin >> a[i];
    for(int i=0;i<n;i++)pref[i+1]=pref[i]+a[i];
 
    for(int j=1;j<=k+1;j++){
        deque<pair<line,int>> q;
        for(int i=1;i<=n;i++){   //maak i = 0
            line l(pref[i-1],dp[i-1][j-1]-pref[i-1]*pref[n]);
            while(q.size()>1&&(l.c-q[1].f.c)*(q[1].f.m-q[0].f.m)<=(q[0].f.c-q[1].f.c)*(q[1].f.m-l.m))q.pop_front();
            q.push_front({l,i-1});

            while(q.size()>1&&q[q.size()-1].f(pref[i])<=q[q.size()-2].f(pref[i]))q.pop_back();

            dp[i][j]=q.back().f(pref[i])-pref[i]*pref[i]+pref[i]*pref[n];
            p[i][j]=q.back().s;
            // for(int x=0;x<i;x++){
                // if(dp[x][j-1]+(pref[i]-pref[x])*(pref[n]-pref[i])>=dp[i][j]){
                //     dp[i][j]=dp[x][j-1]+(pref[i]-pref[x])*(pref[n]-pref[i]);
                //     p[i][j]=x;
                // }
            // }
            // cout << '(' << i << ' ' << j << ')' << dp[i][j] << ' ' << p[i][j] << ' ';
        }
        // cout << '\n';
    }
 
    cout << dp[n][++k] << '\n';
 
    int sus=p[n][k--];
 
    while(k>0){
        cout << sus << ' ';
        sus=p[sus][k--];
    }
 
    return 0;
// 7 3
// 4 1 3 4 0 2 3
 
}

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