Submission #366941

#	Time	Username	Problem	Language	Result	Execution time	Memory
366941		rocks03	Split the sequence (APIO14_sequence)	C++14	0 / 100	87 ms	131076 KiB

sequence

//#pragma GCC target("avx2")
//#pragma GCC optimization("O3")
//#pragma GCC optimization("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MAXK = 200+10;
const int MAXN = 2e5+100;
int N, K, a[MAXN], opt[MAXN][MAXK];
ll pr[MAXN], dp[MAXN][MAXK];

int ck;
double slope(int i, int j){
    return (double) ((dp[i][ck] - pr[i] * pr[N]) - (dp[j][ck] - pr[j] * pr[N])) / (pr[j] - pr[i]);
}

void solve(){
    cin >> N >> K;
    rep(i, 1, N + 1){
        cin >> a[i];
        pr[i] = pr[i - 1] + a[i];
    }
    rep(k, 1, K + 1){
        ck = k - 1;
        deque<int> q;
        q.push_back(0);
        rep(i, 1, N + 1){
            while(SZ(q) > 1 && slope(q[0], q[1]) <= pr[i]){
                q.pop_front();
            }
            int j = q[0];
            dp[i][k] = dp[j][k - 1] + (pr[i] - pr[j]) * (pr[N] - pr[i]);
            opt[i][k] = j;
            while(SZ(q) > 1 && slope(q[SZ(q) - 2], q.back()) >= slope(q.back(), i)){
                q.pop_back();
            }
            q.push_back(i);
        }
    }
    ll ans = 0; int ind = 0;
    rep(i, 1, N){
        if(dp[i][K] >= ans){
            ans = dp[i][K], ind = i;
        }
    }
    cout << ans << "\n";
    per(k, K, 1){
        cout << ind << " ";
        ind = opt[ind][k];
    }
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    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