Submission #393058

#	Time	Username	Problem	Language	Result	Execution time	Memory
393058		arujbansal	Split the sequence (APIO14_sequence)	C++17	100 / 100	1325 ms	81740 KiB

sequence

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <array>
#include <stack>
#include <queue>
#include <random>
#include <numeric>
#include <functional>
#include <chrono>
#include <utility>
#include <iomanip>
#include <assert.h>

using namespace std;

void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)

#define rng_init mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define rng_seed(x) mt19937 rng(x)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
// #define int long long

using ll = long long;

const int MXN = 1e5 + 5;
const ll INF = 1e18;
int N, K;
int A[MXN], trace[205][MXN];
ll dp[2][MXN], pref[MXN];

void dnc(int l, int r, int i, int optl, int optr) {
    if (l > r) return;

    int cur = i & 1;

    int mid = (l + r) / 2;
    pair<ll, ll> best = {-INF, -INF};

    for (int j = optl; j < min(mid, optr + 1); j++) {
        ll new_val = dp[cur ^ 1][j] + (pref[mid] - pref[j]) * (pref[N] - pref[mid]);

        if (new_val > best.first)
            best = make_pair(new_val, j);
    }

    dp[cur][mid] = best.first;
    trace[i][mid] = best.second;

    dnc(l, mid - 1, i, optl, best.second);
    dnc(mid + 1, r, i, best.second, optr);
}

void solve() {
    cin >> N >> K;

    for (int i = 1; i <= N; i++) {
        cin >> A[i];
        pref[i] = pref[i - 1] + A[i];
    }

    for (int i = 0; i < 2; i++)
        for (int j = 0; j < MXN; j++)
            dp[i][j] = -INF;

    dp[0][0] = 0;

    for (int i = 1; i <= K; i++)
        dnc(i, N, i, i - 1, N - 1);

    pair<ll, int> best = {-INF, -INF};
    for (int j = 1; j < N; j++)
        best = max(best, make_pair(dp[K & 1][j], j));

    cout << best.first << "\n";

    int cur_k = K;
    while (cur_k && best.second) {
        cout << best.second << " ";
        best.second = trace[cur_k--][best.second];
    }
}

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

    int TC = 1;
    // cin >> TC;
    while (TC--) solve();
}

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