Submission #329496

#	Time	Username	Problem	Language	Result	Execution time	Memory
329496		denverjin	Split the sequence (APIO14_sequence)	C++14	100 / 100	739 ms	85464 KiB

sequence

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

#define ll long long
#define mp make_pair
#define pb push_back

#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#define rep(i, n) for (int i = 0; i < (int)(n); ++ i)

struct func {
    int k; ll b;
    func(): k(), b() {}
    func(int k, ll b): k(k), b(b) {}
    ll get(int x) { return 1LL * k * x + b; }
    double inter(func o) {
        return -(double)(b - o.b) / (k - o.k);
    }
};

int n, k, a[100005], s[100005];
ll dp[100005], ndp[100005];
int pr[100005][205];
func f[100005];
int que[100005], ql, qr;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> k;
    rep(i, n) cin >> a[i], s[i + 1] = s[i] + a[i];
    rep(j, k) {
        ql = qr = 0;
        rep(i, n) {
            f[i] = func(s[i], dp[i] - 1LL * s[i] * s[i]);
            while (qr - ql >= 2 && f[que[qr - 2]].inter(f[i]) <= f[que[qr - 2]].inter(f[que[qr - 1]])) -- qr;
            que[qr ++] = i;
            while (qr - ql >= 2 && f[que[ql]].get(s[i + 1]) <= f[que[ql + 1]].get(s[i + 1])) ++ ql;
            ndp[i + 1] = f[que[ql]].get(s[i + 1]);
            pr[i + 1][j + 1] = que[ql];
        }
        memcpy(dp, ndp, sizeof(dp));
    }
    cout << dp[n] << endl;
    vector <int> ans;
    int i = n, j = k;
    while (j) i = pr[i][j], -- j, ans.pb(i);
    reverse(ans.begin(), ans.end());
    rep(i, ans.size()) cout << ans[i] << " ";
    cout << endl;
    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: 29 / 29