Submission #724203

#	Time	Username	Problem	Language	Result	Execution time	Memory
724203		colossal_pepe	Split the sequence (APIO14_sequence)	C++17	0 / 100	6 ms	1876 KiB

sequence

#include <iostream>
#include <tuple>
#include <vector>
#include <queue>
using namespace std;

using ll = long long;
using seq = tuple<ll, int, int, int>;

const int N = 1e5;

int n, k;
ll a[N + 5], pfx_sum[N + 5];

seq eval(int L, int R) {
    if (L == R) return make_tuple(0, L, R, L);
    int l = L, r = R;
    while (r - l > 1) {
        int m = (l + r) / 2;
        if (2 * pfx_sum[m] <= pfx_sum[R] - pfx_sum[L - 1]) l = m + 1;
        else r = m;
    }
    if (2 * (pfx_sum[l] - pfx_sum[L - 1]) <= pfx_sum[R] - pfx_sum[L - 1]) l++;
    r = l;
    l--;
    ll x1 = (pfx_sum[l] - pfx_sum[L - 1]) * (pfx_sum[R] - pfx_sum[l]);
    ll x2 = (pfx_sum[r] - pfx_sum[L - 1]) * (pfx_sum[R] - pfx_sum[r]);
    if (x1 < x2) return make_tuple(x2, L, R, r);
    else return make_tuple(x1, L, R, l);
}

ll solve() {
    priority_queue<seq> q;
    q.push(eval(1, n));
    ll ret = 0;
    while (k--) {
        auto [score, l, r, m] = q.top();
        q.pop();
        ret += score;
        q.push(eval(l, m));
        q.push(eval(m + 1, r));
    }
    return ret;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> k;
    pfx_sum[0] = 0;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        pfx_sum[i] = a[i] + pfx_sum[i - 1];
    }
    cout << solve() << '\n';
    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