Submission #670082

#	Time	Username	Problem	Language	Result	Execution time	Memory
670082		JooDdae	Split the sequence (APIO14_sequence)	C++17	71 / 100	113 ms	131072 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int n, k, bt[100100][222];
ll s[100100], dp[100100][222];

deque<array<ll, 3>> t[222];

bool check(int k, int a, int b, int c) {
    return (t[k][b][0]-t[k][a][0]) * (t[k][c][1]-t[k][a][1]) >= (t[k][c][0]-t[k][a][0]) * (t[k][b][1]-t[k][a][1]);
}


void f(int u, int k) {
    if(k == 0) return;
    f(bt[u][k], k-1);
    cout << u << " ";
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> k;
    for(int i=1;i<=n;i++) cin >> s[i];

    for(int i=1;i<=n;i++) s[i] += s[i-1];

    t[0].push_back({s[n], 0, 0});
    int mx = 0;

    for(int i=1;i<n;i++) {
        for(int j=min(i, k);j>=1;j--) {
            int b = int(t[j-1].size())-1;
            while(t[j-1].size() > 2 && check(j-1, b-2, b-1, b)) t[j-1][b-1] = t[j-1][b], b--, t[j-1].pop_back();
            while(t[j-1].size() > 1 && t[j-1][0][0]*s[i]+t[j-1][0][1] <= t[j-1][1][0]*s[i]+t[j-1][1][1]) t[j-1].pop_front();

            auto [X, Y, id] = t[j-1][0];
            dp[i][j] = X*s[i]+Y - s[i]*s[i], bt[i][j] = id;

            t[j].push_back({s[n]+s[i], dp[i][j] - s[n]*s[i], i});
        }
        if(dp[i][k] >= dp[mx][k]) mx = i;
    }

    cout << dp[mx][k] << "\n";
    f(mx, k);
}

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