Submission #735999

#	Time	Username	Problem	Language	Result	Execution time	Memory
735999		GrindMachine	Split the sequence (APIO14_sequence)	C++17	71 / 100	2086 ms	92396 KiB

sequence

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

// https://github.com/kth-competitive-programming/kactl/blob/main/content/data-structures/LineContainer.h
struct Line {
    mutable ll k, m, p, id;
    bool operator<(const Line& o) const { return k < o.k; }
    bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
    // (for doubles, use inf = 1/.0, div(a,b) = a/b)
    static const ll inf = LLONG_MAX;
    ll div(ll a, ll b) { // floored division
        return a / b - ((a ^ b) < 0 && a % b);
    }
    bool isect(iterator x, iterator y) {
        if (y == end()) return x->p = inf, 0;
        if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
        else x->p = div(y->m - x->m, x->k - y->k);
        return x->p >= y->p;
    }
    void add(ll k, ll m, ll id) {
        auto z = insert({k, m, 0, id}), y = z++, x = y;
        while (isect(y, z)) z = erase(z);
        if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
        while ((y = x) != begin() && (--x)->p >= y->p)
            isect(x, erase(y));
    }
    pll query(ll x) {
        assert(!empty());
        auto l = *lower_bound(x);
        return {l.k * x + l.m, l.id};
    }
};

void solve(int test_case)
{
    ll n, k; cin >> n >> k;
    k++;

    vector<ll> a(n + 5);
    rep1(i, n) cin >> a[i];

    vector<ll> pref(n + 5);
    rep1(i, n) pref[i] = pref[i - 1] + a[i];

    int par[n + 5][k + 5];
    memset(par, -1, sizeof par);

    vector<ll> dp1(n + 5, -inf2);
    dp1[0] = 0;

    rep1(t, k) {
        LineContainer cht;
        vector<ll> dp2(n + 5, -inf2);

        rep1(i, n) {
            cht.add(-pref[i - 1], dp1[i - 1], i - 1);
            ll suff = pref[n] - pref[i];
            auto [mx, id] = cht.query(suff);
            mx += pref[i] * suff;
            dp2[i] = mx;
            par[i][t] = id;
        }

        dp1 = dp2;
    }

    ll ans = dp1[n];
    cout << ans << endl;

    ll ptr = n;
    vector<ll> cuts;

    rev(t, k, 1) {
        if (ptr != n) {
            cuts.pb(ptr);
        }
        ptr = par[ptr][t];
    }

    reverse(all(cuts));
    trav(x, cuts) cout << x << " ";
    cout << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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