Submission #1092941

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092941		shivansh0809	Holiday (IOI14_holiday)	C++17	24 / 100	83 ms	65536 KiB

holiday

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

struct PersistentSegTree
{ // find_kth returns the kth smallest element in the array in [l, r)
    struct Vertex
    {
        Vertex *l, *r;
        long long sum;
        long long k_sum;
        Vertex(long long val) : l(nullptr), r(nullptr), sum(val), k_sum(0) {}
        Vertex(long long val, long long k_sum) : l(nullptr), r(nullptr), sum(val), k_sum(k_sum) {}
        Vertex(Vertex *l, Vertex *r) : l(l), r(r), sum(0), k_sum(0)
        {
            if (l)
                sum += l->sum, k_sum += l->k_sum;
            if (r)
                sum += r->sum, k_sum += r->k_sum;
        }
    };

    vector<Vertex *> roots;
    map<long long, pair<long long, long long>> compress;
    long long n;

    PersistentSegTree(vector<long long> v) : n(v.size())
    {
        long long tl = 0, tr = n;
        vector<pair<long long, long long>> sort_v;
        for (long long i = 0; i < n; i++)
            sort_v.push_back({v[i], i});
        sort(sort_v.begin(), sort_v.end(), greater<pair<long long, long long>>());
        vector<long long> idx(n);
        for (long long i = 0; i < n; i++)
            compress[i] = sort_v[i], idx[sort_v[i].second] = i;
        roots.push_back(build(tl, tr));
        for (long long i = 0; i < n; i++)
            roots.push_back(update(roots.back(), tl, tr, idx[i]));
    }

    Vertex *build(long long tl, long long tr)
    {
        if (tl == tr)
            return new Vertex(0LL, 0LL);
        long long tm = (tl + tr) / 2;
        return new Vertex(build(tl, tm), build(tm + 1, tr));
    }
    Vertex *update(Vertex *v, long long tl, long long tr, long long pos)
    {
        if (tl == tr)
            return new Vertex(v->sum + 1, v->k_sum + compress[pos].first);
        long long tm = (tl + tr) / 2;
        if (pos <= tm)
            return new Vertex(update(v->l, tl, tm, pos), v->r);
        else
            return new Vertex(v->l, update(v->r, tm + 1, tr, pos));
    }

    long long find_kth(Vertex *vl, Vertex *vr, long long tl, long long tr, long long k)
    {
        if (tl == tr)
            return vr->k_sum - vl->k_sum;
        long long tm = (tl + tr) / 2;
        long long left_count = vr->l->sum - vl->l->sum;
        if (left_count >= k)
            return find_kth(vl->l, vr->l, tl, tm, k);
        return vr->l->k_sum - vl->l->k_sum + find_kth(vl->r, vr->r, tm + 1, tr, k - left_count);
    }

    long long find_kth(long long l, long long r, long long k)
    {
        return find_kth(roots[l], roots[r], 0, n, k);
    }
};

long long int findMaxAttraction(int n, int start, int d, int attraction[])
{
    long long ans = 0;
    PersistentSegTree pst(vector<long long>(attraction, attraction + n));
    function<long long(long long, long long)> C1 = [&](long long k, long long mid) -> long long
    {
        long long days_rem = d - (mid - k + start - k);
        if (days_rem <= 0)
            return 0;
        return pst.find_kth(k, mid + 1, days_rem);
        // return mid - k;
    };
    function<long long(long long, long long)> C2 = [&](long long mid, long long k) -> long long
    {
        long long days_rem = d - (k - mid + k - start);
        if (days_rem <= 0)
            return 0;
        return pst.find_kth(mid, k + 1, days_rem);
        // return k - mid;
    };
    function<void(long long, long long, long long, long long)> dncg = [&](long long l, long long r, long long optl, long long optr)
    {
        if (l > r)
            return;

        long long mid = (l + r) >> 1;
        pair<long long, long long> best = {-1, -1};

        for (long long k = optl; k <= min(mid, optr); k++)
            best = max(best, {C1(k, mid), k});

        // debug(dp, best, ndp);
        // debug(ans, best, mid);
        ans = max(best.first, ans);
        long long opt = best.second;

        dncg(l, mid - 1, optl, opt);
        dncg(mid + 1, r, opt, optr);
    };
    function<void(long long, long long, long long, long long)> dncs = [&](long long l, long long r, long long optl, long long optr)
    {
        if (l > r)
            return;

        long long mid = (l + r) >> 1;
        pair<long long, long long> best = {-1, -1};

        for (long long k = optr; k >= max(mid, optl); k--)
            best = max(best, {C2(mid, k), k});

        // debug(dp, best, ndp);
        // debug(ans, best, mid);
        ans = max(best.first, ans);
        long long opt = best.second;

        dncs(l, mid - 1, optl, opt);
        dncs(mid + 1, r, opt, optr);
    };
    if (d == 0)
        return 0;
    ans = attraction[start];
    dncg(start + 1, n - 1, 0, start);
    dncs(0, start - 1, start, n - 1);

    return ans;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 23
• Subtask 3: 17 / 17
• Subtask 4: 0 / 53